21107042456 has 8 divisors (see below), whose sum is σ = 39575704620. Its totient is φ = 10553521224.

The previous prime is 21107042443. The next prime is 21107042483. The reversal of 21107042456 is 65424070112.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1319190146 + ... + 1319190161.

Almost surely, 2^21107042456 is an apocalyptic number.

It is an amenable number.

21107042456 is a deficient number, since it is larger than the sum of its proper divisors (18468662164).

21107042456 is a wasteful number, since it uses less digits than its factorization.

21107042456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2638380313 (or 2638380309 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 32.

The spelling of 21107042456 in words is "twenty-one billion, one hundred seven million, forty-two thousand, four hundred fifty-six".