861156660 has 96 divisors (see below), whose sum is σ = 2967697152. Its totient is φ = 181693440.

The previous prime is 861156631. The next prime is 861156671. The reversal of 861156660 is 66651168.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 73401 + ... + 84320.

It is an arithmetic number, because the mean of its divisors is an integer number (30913512).

Almost surely, 2^861156660 is an apocalyptic number.

It is an amenable number.

861156660 is an abundant number, since it is smaller than the sum of its proper divisors (2106540492).

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

861156660 is a wasteful number, since it uses less digits than its factorization.

861156660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157753 (or 157751 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 861156660 is about 29345.4708600833. The cubic root of 861156660 is about 951.3946864667.

The spelling of 861156660 in words is "eight hundred sixty-one million, one hundred fifty-six thousand, six hundred sixty".