21265359012 has 72 divisors (see below), whose sum is σ = 54074704320. Its totient is φ = 7046262720.

The previous prime is 21265358987. The next prime is 21265359077. The reversal of 21265359012 is 21095356212.

It is a happy number.

21265359012 is a `hidden beast` number, since 2 + 1 + 2 + 6 + 53 + 590 + 12 = 666.

It is a super-2 number, since 2×21265359012² (a number of 21 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10428289 + ... + 10430327.

It is an arithmetic number, because the mean of its divisors is an integer number (751037560).

Almost surely, 2^21265359012 is an apocalyptic number.

It is an amenable number.

21265359012 is an abundant number, since it is smaller than the sum of its proper divisors (32809345308).

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

21265359012 is a wasteful number, since it uses less digits than its factorization.

21265359012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3633 (or 3628 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The spelling of 21265359012 in words is "twenty-one billion, two hundred sixty-five million, three hundred fifty-nine thousand, twelve".