20138404 has 96 divisors (see below), whose sum is σ = 46569600. Its totient is φ = 7464960.

The previous prime is 20138389. The next prime is 20138407. The reversal of 20138404 is 40483102.

20138404 = T₇₇ + T₇₈ + ... + T₄₉₄.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20138407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 184702 + ... + 184810.

It is an arithmetic number, because the mean of its divisors is an integer number (485100).

Almost surely, 2^20138404 is an apocalyptic number.

It is an amenable number.

20138404 is an abundant number, since it is smaller than the sum of its proper divisors (26431196).

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

20138404 is a wasteful number, since it uses less digits than its factorization.

20138404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173 (or 171 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 20138404 is about 4487.5833139898. The cubic root of 20138404 is about 272.0664665999.

The spelling of 20138404 in words is "twenty million, one hundred thirty-eight thousand, four hundred four".