21118398 has 16 divisors (see below), whose sum is σ = 48270720. Its totient is φ = 6033816.

The previous prime is 21118381. The next prime is 21118411. The reversal of 21118398 is 89381112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 251368 + ... + 251451.

It is an arithmetic number, because the mean of its divisors is an integer number (3016920).

Almost surely, 2^21118398 is an apocalyptic number.

21118398 is an abundant number, since it is smaller than the sum of its proper divisors (27152322).

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

21118398 is a wasteful number, since it uses less digits than its factorization.

21118398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502831.

The product of its digits is 3456, while the sum is 33.

The square root of 21118398 is about 4595.4758186721. The cubic root of 21118398 is about 276.4099400730.

The spelling of 21118398 in words is "twenty-one million, one hundred eighteen thousand, three hundred ninety-eight".