861685766 has 64 divisors (see below), whose sum is σ = 1454967360. Its totient is φ = 380989440.

The previous prime is 861685763. The next prime is 861685771. The reversal of 861685766 is 667586168.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861685763) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7905320 + ... + 7905428.

It is an arithmetic number, because the mean of its divisors is an integer number (22733865).

Almost surely, 2^861685766 is an apocalyptic number.

861685766 is a deficient number, since it is larger than the sum of its proper divisors (593281594).

861685766 is a wasteful number, since it uses less digits than its factorization.

861685766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329.

The product of its digits is 2903040, while the sum is 53.

The square root of 861685766 is about 29354.4845977578. The cubic root of 861685766 is about 951.5894963851.

The spelling of 861685766 in words is "eight hundred sixty-one million, six hundred eighty-five thousand, seven hundred sixty-six".