21563231634516 has 192 divisors, whose sum is σ = 59763830821632. Its totient is φ = 5965132800000.

The previous prime is 21563231634443. The next prime is 21563231634521. The reversal of 21563231634516 is 61543613236512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 152620786 + ... + 152762006.

It is an arithmetic number, because the mean of its divisors is an integer number (311269952196).

Almost surely, 2^{21563231634516} is an apocalyptic number.

21563231634516 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21563231634516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29881915410816).

21563231634516 is an abundant number, since it is smaller than the sum of its proper divisors (38200599187116).

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

21563231634516 is a wasteful number, since it uses less digits than its factorization.

21563231634516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142234 (or 142232 counting only the distinct ones).

The product of its digits is 2332800, while the sum is 48.

The spelling of 21563231634516 in words is "twenty-one trillion, five hundred sixty-three billion, two hundred thirty-one million, six hundred thirty-four thousand, five hundred sixteen".