172138807 has 4 divisors (see below), whose sum is σ = 172186960. Its totient is φ = 172090656.

The previous prime is 172138789. The next prime is 172138817. The reversal of 172138807 is 708831271.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 172138807 - 2⁷ = 172138679 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172138817) 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, 18243 + ... + 26020.

It is an arithmetic number, because the mean of its divisors is an integer number (43046740).

Almost surely, 2^172138807 is an apocalyptic number.

172138807 is a deficient number, since it is larger than the sum of its proper divisors (48153).

172138807 is an equidigital number, since it uses as much as digits as its factorization.

172138807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48152.

The product of its (nonzero) digits is 18816, while the sum is 37.

The square root of 172138807 is about 13120.1679486202. The cubic root of 172138807 is about 556.2793385695.

The spelling of 172138807 in words is "one hundred seventy-two million, one hundred thirty-eight thousand, eight hundred seven".