20138172 has 12 divisors (see below), whose sum is σ = 46989096. Its totient is φ = 6712720.

The previous prime is 20138171. The next prime is 20138191. The reversal of 20138172 is 27183102.

It is a tau number, because it is divible by the number of its divisors (12).

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20138171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 839079 + ... + 839102.

It is an arithmetic number, because the mean of its divisors is an integer number (3915758).

Almost surely, 2^20138172 is an apocalyptic number.

It is an amenable number.

20138172 is an abundant number, since it is smaller than the sum of its proper divisors (26850924).

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

20138172 is a wasteful number, since it uses less digits than its factorization.

20138172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1678188 (or 1678186 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 20138172 is about 4487.5574648131. The cubic root of 20138172 is about 272.0654218355.

The spelling of 20138172 in words is "twenty million, one hundred thirty-eight thousand, one hundred seventy-two".