20138418 has 24 divisors (see below), whose sum is σ = 44350956. Its totient is φ = 6602400.

The previous prime is 20138413. The next prime is 20138431. The reversal of 20138418 is 81483102.

It can be written as a sum of positive squares in 2 ways, for example, as 14953689 + 5184729 = 3867^2 + 2277^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20138391 and 20138400.

It is not an unprimeable number, because it can be changed into a prime (20138413) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8073 + ... + 10268.

Almost surely, 2^20138418 is an apocalyptic number.

20138418 is an abundant number, since it is smaller than the sum of its proper divisors (24212538).

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

20138418 is a wasteful number, since it uses less digits than its factorization.

20138418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18410 (or 18407 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 20138418 is about 4487.5848738492. The cubic root of 20138418 is about 272.0665296457.

The spelling of 20138418 in words is "twenty million, one hundred thirty-eight thousand, four hundred eighteen".