21661251614502 has 32 divisors (see below), whose sum is σ = 43333364448000. Its totient is φ = 7218607236768.

The previous prime is 21661251614491. The next prime is 21661251614537. The reversal of 21661251614502 is 20541615216612.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 587023249 + ... + 587060147.

It is an arithmetic number, because the mean of its divisors is an integer number (1354167639000).

Almost surely, 2^{21661251614502} is an apocalyptic number.

21661251614502 is an abundant number, since it is smaller than the sum of its proper divisors (21672112833498).

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

21661251614502 is a wasteful number, since it uses less digits than its factorization.

21661251614502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58780.

The product of its (nonzero) digits is 172800, while the sum is 42.

The spelling of 21661251614502 in words is "twenty-one trillion, six hundred sixty-one billion, two hundred fifty-one million, six hundred fourteen thousand, five hundred two".