21638514 has 32 divisors (see below), whose sum is σ = 44328960. Its totient is φ = 7039872.

The previous prime is 21638509. The next prime is 21638531. The reversal of 21638514 is 41583612.

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, 55432 + ... + 55820.

It is an arithmetic number, because the mean of its divisors is an integer number (1385280).

Almost surely, 2^21638514 is an apocalyptic number.

21638514 is an abundant number, since it is smaller than the sum of its proper divisors (22690446).

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

21638514 is a wasteful number, since it uses less digits than its factorization.

21638514 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 594.

The product of its digits is 5760, while the sum is 30.

The square root of 21638514 is about 4651.7216167780. The cubic root of 21638514 is about 278.6607559496.

The spelling of 21638514 in words is "twenty-one million, six hundred thirty-eight thousand, five hundred fourteen".