21250251042650 has 48 divisors (see below), whose sum is σ = 45172329012096. Its totient is φ = 7285741197120.

The previous prime is 21250251042607. The next prime is 21250251042661. The reversal of 21250251042650 is 5624015205212.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 21250251042650.

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, 83718227 + ... + 83971673.

It is an arithmetic number, because the mean of its divisors is an integer number (941090187752).

Almost surely, 2^{21250251042650} is an apocalyptic number.

21250251042650 is an abundant number, since it is smaller than the sum of its proper divisors (23922077969446).

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

21250251042650 is a wasteful number, since it uses less digits than its factorization.

21250251042650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 493023 (or 493018 counting only the distinct ones).

The product of its (nonzero) digits is 48000, while the sum is 35.

Adding to 21250251042650 its reverse (5624015205212), we get a palindrome (26874266247862).

The spelling of 21250251042650 in words is "twenty-one trillion, two hundred fifty billion, two hundred fifty-one million, forty-two thousand, six hundred fifty".