172978945 has 16 divisors (see below), whose sum is σ = 219199680. Its totient is φ = 130680000.

The previous prime is 172978943. The next prime is 172978951. The reversal of 172978945 is 549879271.

It is not a de Polignac number, because 172978945 - 2¹ = 172978943 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 172978892 and 172978901.

It is not an unprimeable number, because it can be changed into a prime (172978943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28695 + ... + 34195.

It is an arithmetic number, because the mean of its divisors is an integer number (13699980).

Almost surely, 2^172978945 is an apocalyptic number.

It is an amenable number.

172978945 is a deficient number, since it is larger than the sum of its proper divisors (46220735).

172978945 is a wasteful number, since it uses less digits than its factorization.

172978945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5856.

The product of its digits is 1270080, while the sum is 52.

The square root of 172978945 is about 13152.1460226079. The cubic root of 172978945 is about 557.1828597025.

The spelling of 172978945 in words is "one hundred seventy-two million, nine hundred seventy-eight thousand, nine hundred forty-five".