21621361553512 has 16 divisors (see below), whose sum is σ = 46331489043360. Its totient is φ = 9266297808624.

The previous prime is 21621361553497. The next prime is 21621361553531. The reversal of 21621361553512 is 21535516312612.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 193047870958 + ... + 193047871069.

It is an arithmetic number, because the mean of its divisors is an integer number (2895718065210).

Almost surely, 2^{21621361553512} is an apocalyptic number.

It is an amenable number.

21621361553512 is an abundant number, since it is smaller than the sum of its proper divisors (24710127489848).

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

21621361553512 is a wasteful number, since it uses less digits than its factorization.

21621361553512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386095742040 (or 386095742036 counting only the distinct ones).

The product of its digits is 324000, while the sum is 43.

The spelling of 21621361553512 in words is "twenty-one trillion, six hundred twenty-one billion, three hundred sixty-one million, five hundred fifty-three thousand, five hundred twelve".