172156197789 has 24 divisors (see below), whose sum is σ = 251530531200. Its totient is φ = 113451264960.

The previous prime is 172156197761. The next prime is 172156197793. The reversal of 172156197789 is 987791651271.

172156197789 is a `hidden beast` number, since 1 + 7 + 2 + 1 + 5 + 619 + 7 + 7 + 8 + 9 = 666.

172156197789 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 172156197789 - 2²¹ = 172154100637 is a prime.

It is a hoax number, since the sum of its digits (63) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172156197739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3240934 + ... + 3293624.

It is an arithmetic number, because the mean of its divisors is an integer number (10480438800).

Almost surely, 2^172156197789 is an apocalyptic number.

It is an amenable number.

172156197789 is a deficient number, since it is larger than the sum of its proper divisors (79374333411).

172156197789 is a wasteful number, since it uses less digits than its factorization.

172156197789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56865 (or 56862 counting only the distinct ones).

The product of its digits is 13335840, while the sum is 63.

The spelling of 172156197789 in words is "one hundred seventy-two billion, one hundred fifty-six million, one hundred ninety-seven thousand, seven hundred eighty-nine".