21251515262 has 4 divisors (see below), whose sum is σ = 31877272896. Its totient is φ = 10625757630.

The previous prime is 21251515247. The next prime is 21251515289. The reversal of 21251515262 is 26251515212.

It is a happy number.

It is a semiprime because it is the product of two primes.

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 as a sum of consecutive naturals, namely, 5312878814 + ... + 5312878817.

It is an arithmetic number, because the mean of its divisors is an integer number (7969318224).

Almost surely, 2^21251515262 is an apocalyptic number.

21251515262 is a deficient number, since it is larger than the sum of its proper divisors (10625757634).

21251515262 is a wasteful number, since it uses less digits than its factorization.

21251515262 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10625757633.

The product of its digits is 12000, while the sum is 32.

The spelling of 21251515262 in words is "twenty-one billion, two hundred fifty-one million, five hundred fifteen thousand, two hundred sixty-two".