21638824721284 has 12 divisors (see below), whose sum is σ = 37884050443008. Its totient is φ = 10814810309000.

The previous prime is 21638824721263. The next prime is 21638824721299. The reversal of 21638824721284 is 48212742883612.

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, 1150502332 + ... + 1150521139.

It is an arithmetic number, because the mean of its divisors is an integer number (3157004203584).

Almost surely, 2^{21638824721284} is an apocalyptic number.

It is an amenable number.

21638824721284 is a deficient number, since it is larger than the sum of its proper divisors (16245225721724).

21638824721284 is a wasteful number, since it uses less digits than its factorization.

21638824721284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2301025826 (or 2301025824 counting only the distinct ones).

The product of its digits is 16515072, while the sum is 58.

The spelling of 21638824721284 in words is "twenty-one trillion, six hundred thirty-eight billion, eight hundred twenty-four million, seven hundred twenty-one thousand, two hundred eighty-four".