861998180 has 24 divisors (see below), whose sum is σ = 1811261760. Its totient is φ = 344596320.

The previous prime is 861998173. The next prime is 861998191. The reversal of 861998180 is 81899168.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24851 + ... + 48389.

It is an arithmetic number, because the mean of its divisors is an integer number (75469240).

Almost surely, 2^861998180 is an apocalyptic number.

It is an amenable number.

861998180 is an abundant number, since it is smaller than the sum of its proper divisors (949263580).

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

861998180 is a wasteful number, since it uses less digits than its factorization.

861998180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25379 (or 25377 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 50.

The square root of 861998180 is about 29359.8055170670. The cubic root of 861998180 is about 951.7044856969.

The spelling of 861998180 in words is "eight hundred sixty-one million, nine hundred ninety-eight thousand, one hundred eighty".