172394987905 has 32 divisors (see below), whose sum is σ = 237406924800. Its totient is φ = 117724985280.

The previous prime is 172394987903. The next prime is 172394987927. The reversal of 172394987905 is 509789493271.

It is not a de Polignac number, because 172394987905 - 2¹ = 172394987903 is a prime.

It is not an unprimeable number, because it can be changed into a prime (172394987903) 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 31 ways as a sum of consecutive naturals, for example, 8358796 + ... + 8379394.

It is an arithmetic number, because the mean of its divisors is an integer number (7418966400).

Almost surely, 2^172394987905 is an apocalyptic number.

It is an amenable number.

172394987905 is a deficient number, since it is larger than the sum of its proper divisors (65011936895).

172394987905 is a wasteful number, since it uses less digits than its factorization.

172394987905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21589.

The product of its (nonzero) digits is 34292160, while the sum is 64.

The spelling of 172394987905 in words is "one hundred seventy-two billion, three hundred ninety-four million, nine hundred eighty-seven thousand, nine hundred five".