21046562556 has 12 divisors (see below), whose sum is σ = 49108645992. Its totient is φ = 7015520848.

The previous prime is 21046562503. The next prime is 21046562587. The reversal of 21046562556 is 65526564012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 876940095 + ... + 876940118.

It is an arithmetic number, because the mean of its divisors is an integer number (4092387166).

Almost surely, 2^21046562556 is an apocalyptic number.

It is an amenable number.

21046562556 is an abundant number, since it is smaller than the sum of its proper divisors (28062083436).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21046562556 is a wasteful number, since it uses less digits than its factorization.

21046562556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1753880220 (or 1753880218 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 42.

The spelling of 21046562556 in words is "twenty-one billion, forty-six million, five hundred sixty-two thousand, five hundred fifty-six".