20638878 has 16 divisors (see below), whose sum is σ = 44453136. Its totient is φ = 6350400.

The previous prime is 20638861. The next prime is 20638931. The reversal of 20638878 is 87883602.

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, 132223 + ... + 132378.

It is an arithmetic number, because the mean of its divisors is an integer number (2778321).

Almost surely, 2^20638878 is an apocalyptic number.

20638878 is an abundant number, since it is smaller than the sum of its proper divisors (23814258).

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

20638878 is a wasteful number, since it uses less digits than its factorization.

20638878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264619.

The product of its (nonzero) digits is 129024, while the sum is 42.

The square root of 20638878 is about 4543.0031917224. The cubic root of 20638878 is about 274.3018234431.

The spelling of 20638878 in words is "twenty million, six hundred thirty-eight thousand, eight hundred seventy-eight".