20638400 has 42 divisors (see below), whose sum is σ = 50787300. Its totient is φ = 8254720.

The previous prime is 20638379. The next prime is 20638417. The reversal of 20638400 is 483602.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4850 + ... + 8049.

Almost surely, 2^20638400 is an apocalyptic number.

20638400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20638400 is an abundant number, since it is smaller than the sum of its proper divisors (30148900).

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

20638400 is a wasteful number, since it uses less digits than its factorization.

20638400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12921 (or 12906 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 20638400 is about 4542.9505830462. The cubic root of 20638400 is about 274.2997058008.

The spelling of 20638400 in words is "twenty million, six hundred thirty-eight thousand, four hundred".