21265276320 has 72 divisors (see below), whose sum is σ = 72567760356. Its totient is φ = 5670739968.

The previous prime is 21265276309. The next prime is 21265276453. The reversal of 21265276320 is 2367256212.

21265276320 is a `hidden beast` number, since 2 + 1 + 2 + 65 + 276 + 320 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 20774033424 + 491242896 = 144132^2 + 22164^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-3 number, since 3×21265276320³ (a number of 32 digits) contains 333 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 11 ways as a sum of consecutive naturals, for example, 7382337 + ... + 7385216.

Almost surely, 2^21265276320 is an apocalyptic number.

21265276320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21265276320 is an abundant number, since it is smaller than the sum of its proper divisors (51302484036).

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

21265276320 is a wasteful number, since it uses less digits than its factorization.

21265276320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14767574 (or 14767563 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The spelling of 21265276320 in words is "twenty-one billion, two hundred sixty-five million, two hundred seventy-six thousand, three hundred twenty".