211111761961 has 3 divisors (see below), whose sum is σ = 211112221431. Its totient is φ = 211111302492.

The previous prime is 211111761943. The next prime is 211111761979. The reversal of 211111761961 is 169167111112.

The square root of 211111761961 is 459469.

It is a perfect power (a square), and thus also a powerful number.

211111761961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (211111761943) and next prime (211111761979).

It can be written as a sum of positive squares in only one way, i.e., 204106071961 + 7005690000 = 451781^2 + 83700^2 .

It is not a de Polignac number, because 211111761961 - 2⁹ = 211111761449 is a prime.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 211111761961.

It is not an unprimeable number, because it can be changed into a prime (211111765961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 229735 + ... + 689203.

It is an arithmetic number, because the mean of its divisors is an integer number (70370740477).

Almost surely, 2^211111761961 is an apocalyptic number.

211111761961 is the 459469-th square number.

211111761961 is the 229735-th centered octagonal number.

It is an amenable number.

211111761961 is a deficient number, since it is larger than the sum of its proper divisors (459470).

211111761961 is an frugal number, since it uses more digits than its factorization.

211111761961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 918938 (or 459469 counting only the distinct ones).

The product of its digits is 4536, while the sum is 37.

The spelling of 211111761961 in words is "two hundred eleven billion, one hundred eleven million, seven hundred sixty-one thousand, nine hundred sixty-one".