21259551312 has 60 divisors (see below), whose sum is σ = 60385262080. Its totient is φ = 6980745024.

The previous prime is 21259551311. The next prime is 21259551319. The reversal of 21259551312 is 21315595212.

21259551312 is a `hidden beast` number, since 2 + 1 + 2 + 595 + 51 + 3 + 12 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21259551311) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1092112 + ... + 1111407.

Almost surely, 2^21259551312 is an apocalyptic number.

It is an amenable number.

21259551312 is an abundant number, since it is smaller than the sum of its proper divisors (39125710768).

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

21259551312 is a wasteful number, since it uses less digits than its factorization.

21259551312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2203600 (or 2203591 counting only the distinct ones).

The product of its digits is 27000, while the sum is 36.

The spelling of 21259551312 in words is "twenty-one billion, two hundred fifty-nine million, five hundred fifty-one thousand, three hundred twelve".