21251015212 has 36 divisors (see below), whose sum is σ = 44752765680. Its totient is φ = 8793521184.

The previous prime is 21251015167. The next prime is 21251015213.

It is a happy number.

21251015212 is nontrivially palindromic in base 10.

It is not an unprimeable number, because it can be changed into a prime (21251015213) 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, 1863688 + ... + 1875055.

It is an arithmetic number, because the mean of its divisors is an integer number (1243132380).

Almost surely, 2^21251015212 is an apocalyptic number.

It is an amenable number.

21251015212 is an abundant number, since it is smaller than the sum of its proper divisors (23501750468).

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

21251015212 is a wasteful number, since it uses less digits than its factorization.

21251015212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3738790 (or 3738781 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 22.

It can be divided in two parts, 212510 and 15212, that added together give a palindrome (227722).

The spelling of 21251015212 in words is "twenty-one billion, two hundred fifty-one million, fifteen thousand, two hundred twelve".