172138403 has 12 divisors (see below), whose sum is σ = 179356320. Its totient is φ = 165199776.

The previous prime is 172138397. The next prime is 172138433. The reversal of 172138403 is 304831271.

172138403 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 172138403 - 2⁸ = 172138147 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172138433) 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, 165158 + ... + 166196.

It is an arithmetic number, because the mean of its divisors is an integer number (14946360).

Almost surely, 2^172138403 is an apocalyptic number.

172138403 is a deficient number, since it is larger than the sum of its proper divisors (7217917).

172138403 is a wasteful number, since it uses less digits than its factorization.

172138403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1294 (or 1265 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 172138403 is about 13120.1525524668. The cubic root of 172138403 is about 556.2789033839.

Adding to 172138403 its reverse (304831271), we get a palindrome (476969674).

The spelling of 172138403 in words is "one hundred seventy-two million, one hundred thirty-eight thousand, four hundred three".