21118356390 has 32 divisors (see below), whose sum is σ = 50759414496. Its totient is φ = 5623188480.

The previous prime is 21118356353. The next prime is 21118356421. The reversal of 21118356390 is 9365381112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 502801 + ... + 543180.

It is an arithmetic number, because the mean of its divisors is an integer number (1586231703).

Almost surely, 2^21118356390 is an apocalyptic number.

21118356390 is an abundant number, since it is smaller than the sum of its proper divisors (29641058106).

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

21118356390 is a wasteful number, since it uses less digits than its factorization.

21118356390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1046664.

The product of its (nonzero) digits is 38880, while the sum is 39.

The spelling of 21118356390 in words is "twenty-one billion, one hundred eighteen million, three hundred fifty-six thousand, three hundred ninety".