21056164532 has 12 divisors (see below), whose sum is σ = 39682771716. Its totient is φ = 9718229760.

The previous prime is 21056164511. The next prime is 21056164537. The reversal of 21056164532 is 23546165012.

It can be written as a sum of positive squares in 2 ways, for example, as 9313408036 + 11742756496 = 96506^2 + 108364^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21056164492 and 21056164501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21056164537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 202463069 + ... + 202463172.

It is an arithmetic number, because the mean of its divisors is an integer number (3306897643).

Almost surely, 2^21056164532 is an apocalyptic number.

It is an amenable number.

21056164532 is a deficient number, since it is larger than the sum of its proper divisors (18626607184).

21056164532 is a wasteful number, since it uses less digits than its factorization.

21056164532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404926258 (or 404926256 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 35.

The spelling of 21056164532 in words is "twenty-one billion, fifty-six million, one hundred sixty-four thousand, five hundred thirty-two".