212122222211981 has 8 divisors (see below), whose sum is σ = 212163331019640. Its totient is φ = 212081115451392.

The previous prime is 212122222211953. The next prime is 212122222211993. The reversal of 212122222211981 is 189112222221212.

It can be written as a sum of positive squares in 4 ways, for example, as 94181862010756 + 117940360201225 = 9704734^2 + 10860035^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212122222211981 is a prime.

It is a super-2 number, since 2×212122222211981² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212122222211381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 215543885 + ... + 216525773.

It is an arithmetic number, because the mean of its divisors is an integer number (26520416377455).

Almost surely, 2^{212122222211981} is an apocalyptic number.

It is an amenable number.

212122222211981 is a deficient number, since it is larger than the sum of its proper divisors (41108807659).

212122222211981 is an equidigital number, since it uses as much as digits as its factorization.

212122222211981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1023535.

The product of its digits is 18432, while the sum is 38.

The spelling of 212122222211981 in words is "two hundred twelve trillion, one hundred twenty-two billion, two hundred twenty-two million, two hundred eleven thousand, nine hundred eighty-one".