20138688 has 42 divisors (see below), whose sum is σ = 57725564. Its totient is φ = 6712704.

The previous prime is 20138669. The next prime is 20138707. The reversal of 20138688 is 88683102.

It is an interprime number because it is at equal distance from previous prime (20138669) and next prime (20138707).

It is a super-2 number, since 2×20138688² = 811133508722688, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 16906 + ... + 18057.

Almost surely, 2^20138688 is an apocalyptic number.

It is an amenable number.

20138688 is an abundant number, since it is smaller than the sum of its proper divisors (37586876).

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

20138688 is a wasteful number, since it uses less digits than its factorization.

20138688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34981 (or 34968 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 20138688 is about 4487.6149567448. The cubic root of 20138688 is about 272.0677455247.

It can be divided in two parts, 2013 and 8688, that added together give a palindrome (10701).

The spelling of 20138688 in words is "twenty million, one hundred thirty-eight thousand, six hundred eighty-eight".