21051551404 has 48 divisors (see below), whose sum is σ = 40915203840. Its totient is φ = 9416796480.

The previous prime is 21051551387. The next prime is 21051551447. The reversal of 21051551404 is 40415515012.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 169507 + ... + 266149.

It is an arithmetic number, because the mean of its divisors is an integer number (852400080).

Almost surely, 2^21051551404 is an apocalyptic number.

It is an amenable number.

21051551404 is a deficient number, since it is larger than the sum of its proper divisors (19863652436).

21051551404 is a wasteful number, since it uses less digits than its factorization.

21051551404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96790 (or 96788 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 28.

The spelling of 21051551404 in words is "twenty-one billion, fifty-one million, five hundred fifty-one thousand, four hundred four".