861557172 has 48 divisors (see below), whose sum is σ = 2376716160. Its totient is φ = 237670272.

The previous prime is 861557171. The next prime is 861557183. The reversal of 861557172 is 271755168.

861557172 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861557171) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 174403 + ... + 179274.

It is an arithmetic number, because the mean of its divisors is an integer number (49514920).

Almost surely, 2^861557172 is an apocalyptic number.

It is an amenable number.

861557172 is an abundant number, since it is smaller than the sum of its proper divisors (1515158988).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

861557172 is a wasteful number, since it uses less digits than its factorization.

861557172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353720 (or 353718 counting only the distinct ones).

The product of its digits is 117600, while the sum is 42.

The square root of 861557172 is about 29352.2941522464. The cubic root of 861557172 is about 951.5421570911.

The spelling of 861557172 in words is "eight hundred sixty-one million, five hundred fifty-seven thousand, one hundred seventy-two".