21616623503520 has 96 divisors (see below), whose sum is σ = 68172192248832. Its totient is φ = 5757674990592.

The previous prime is 21616623503509. The next prime is 21616623503521. The reversal of 21616623503520 is 2530532661612.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (21616623503521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25988352 + ... + 26807231.

It is an arithmetic number, because the mean of its divisors is an integer number (710127002592).

Almost surely, 2^{21616623503520} is an apocalyptic number.

21616623503520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21616623503520 is an abundant number, since it is smaller than the sum of its proper divisors (46555568745312).

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

21616623503520 is a wasteful number, since it uses less digits than its factorization.

21616623503520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52796454 (or 52796446 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 42.

The spelling of 21616623503520 in words is "twenty-one trillion, six hundred sixteen billion, six hundred twenty-three million, five hundred three thousand, five hundred twenty".