21255970479 has 8 divisors (see below), whose sum is σ = 28521812400. Its totient is φ = 14080387776.

The previous prime is 21255970441. The next prime is 21255970487. The reversal of 21255970479 is 97407955212.

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

It is not a de Polignac number, because 21255970479 - 2¹² = 21255966383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255970499) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22564254 + ... + 22565195.

It is an arithmetic number, because the mean of its divisors is an integer number (3565226550).

Almost surely, 2^21255970479 is an apocalyptic number.

21255970479 is a deficient number, since it is larger than the sum of its proper divisors (7265841921).

21255970479 is a wasteful number, since it uses less digits than its factorization.

21255970479 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45129609.

The product of its (nonzero) digits is 1587600, while the sum is 51.

The spelling of 21255970479 in words is "twenty-one billion, two hundred fifty-five million, nine hundred seventy thousand, four hundred seventy-nine".