21255970478 has 8 divisors (see below), whose sum is σ = 32044177200. Its totient is φ = 10574578080.

The previous prime is 21255970441. The next prime is 21255970487. The reversal of 21255970478 is 87407955212.

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

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, 26703083 + ... + 26703878.

It is an arithmetic number, because the mean of its divisors is an integer number (4005522150).

Almost surely, 2^21255970478 is an apocalyptic number.

21255970478 is a deficient number, since it is larger than the sum of its proper divisors (10788206722).

21255970478 is a wasteful number, since it uses less digits than its factorization.

21255970478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53407162.

The product of its (nonzero) digits is 1411200, while the sum is 50.

The spelling of 21255970478 in words is "twenty-one billion, two hundred fifty-five million, nine hundred seventy thousand, four hundred seventy-eight".