21551602016 has 24 divisors (see below), whose sum is σ = 48491105040. Its totient is φ = 9236400768.

The previous prime is 21551601983. The next prime is 21551602043. The reversal of 21551602016 is 61020615512.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21551602016.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48106031 + ... + 48106478.

It is an arithmetic number, because the mean of its divisors is an integer number (2020462710).

Almost surely, 2^21551602016 is an apocalyptic number.

It is an amenable number.

21551602016 is an abundant number, since it is smaller than the sum of its proper divisors (26939503024).

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

21551602016 is an equidigital number, since it uses as much as digits as its factorization.

21551602016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96212526 (or 96212518 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 29.

The spelling of 21551602016 in words is "twenty-one billion, five hundred fifty-one million, six hundred two thousand, sixteen".