21551503216 has 20 divisors (see below), whose sum is σ = 41796258400. Its totient is φ = 10765372032.

The previous prime is 21551503213. The next prime is 21551503219. The reversal of 21551503216 is 61230515512.

It is an interprime number because it is at equal distance from previous prime (21551503213) and next prime (21551503219).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21551503213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 631581 + ... + 664828.

It is an arithmetic number, because the mean of its divisors is an integer number (2089812920).

Almost surely, 2^21551503216 is an apocalyptic number.

It is an amenable number.

21551503216 is a deficient number, since it is larger than the sum of its proper divisors (20244755184).

21551503216 is a wasteful number, since it uses less digits than its factorization.

21551503216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1297456 (or 1297450 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 31.

The spelling of 21551503216 in words is "twenty-one billion, five hundred fifty-one million, five hundred three thousand, two hundred sixteen".