21608118 has 36 divisors (see below), whose sum is σ = 54463500. Its totient is φ = 6173496.

The previous prime is 21608113. The next prime is 21608123. The reversal of 21608118 is 81180612.

It is an interprime number because it is at equal distance from previous prime (21608113) and next prime (21608123).

It is a junction number, because it is equal to n+sod(n) for n = 21608091 and 21608100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21608113) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 11368 + ... + 13131.

It is an arithmetic number, because the mean of its divisors is an integer number (1512875).

Almost surely, 2^21608118 is an apocalyptic number.

21608118 is an abundant number, since it is smaller than the sum of its proper divisors (32855382).

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

21608118 is a wasteful number, since it uses less digits than its factorization.

21608118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24521 (or 24511 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 27.

The square root of 21608118 is about 4648.4532911496. The cubic root of 21608118 is about 278.5302149229.

The spelling of 21608118 in words is "twenty-one million, six hundred eight thousand, one hundred eighteen".