211691089801 has 3 divisors (see below), whose sum is σ = 211691549901. Its totient is φ = 211690629702.

The previous prime is 211691089763. The next prime is 211691089811. The reversal of 211691089801 is 108980196112.

The square root of 211691089801 is 460099.

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

211691089801 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 not a de Polignac number, because 211691089801 - 2²⁷ = 211556872073 is a prime.

It is a super-2 number, since 2×211691089801² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (211691089811) 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, 230050 + ... + 690148.

It is an arithmetic number, because the mean of its divisors is an integer number (70563849967).

Almost surely, 2^211691089801 is an apocalyptic number.

211691089801 is the 460099-th square number.

211691089801 is the 230050-th centered octagonal number.

It is an amenable number.

211691089801 is a deficient number, since it is larger than the sum of its proper divisors (460100).

211691089801 is an frugal number, since it uses more digits than its factorization.

211691089801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 920198 (or 460099 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 46.

The spelling of 211691089801 in words is "two hundred eleven billion, six hundred ninety-one million, eighty-nine thousand, eight hundred one".