861372180 has 36 divisors (see below), whose sum is σ = 2612829492. Its totient is φ = 229699200.

The previous prime is 861372151. The next prime is 861372203. The reversal of 861372180 is 81273168.

It can be written as a sum of positive squares in 2 ways, for example, as 557148816 + 304223364 = 23604^2 + 17442^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2392521 + ... + 2392880.

It is an arithmetic number, because the mean of its divisors is an integer number (72578597).

Almost surely, 2^861372180 is an apocalyptic number.

It is an amenable number.

861372180 is an abundant number, since it is smaller than the sum of its proper divisors (1751457312).

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

861372180 is a wasteful number, since it uses less digits than its factorization.

861372180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4785416 (or 4785411 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 861372180 is about 29349.1427472763. The cubic root of 861372180 is about 951.4740477449.

The spelling of 861372180 in words is "eight hundred sixty-one million, three hundred seventy-two thousand, one hundred eighty".