21258255960 has 48 divisors (see below), whose sum is σ = 69089333040. Its totient is φ = 5668868160.

The previous prime is 21258255959. The next prime is 21258255989. The reversal of 21258255960 is 6955285212.

21258255960 is a `hidden beast` number, since 2 + 1 + 2 + 58 + 2 + 5 + 596 + 0 = 666.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29524996 + ... + 29525715.

It is an arithmetic number, because the mean of its divisors is an integer number (1439361105).

Almost surely, 2^21258255960 is an apocalyptic number.

21258255960 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21258255960 is an abundant number, since it is smaller than the sum of its proper divisors (47831077080).

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

21258255960 is a wasteful number, since it uses less digits than its factorization.

21258255960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59050728 (or 59050721 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 45.

The spelling of 21258255960 in words is "twenty-one billion, two hundred fifty-eight million, two hundred fifty-five thousand, nine hundred sixty".