865899666 has 32 divisors (see below), whose sum is σ = 1938081600. Its totient is φ = 286554240.

The previous prime is 865899649. The next prime is 865899691. The reversal of 865899666 is 666998568.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50175 + ... + 65186.

It is an arithmetic number, because the mean of its divisors is an integer number (60565050).

Almost surely, 2^865899666 is an apocalyptic number.

865899666 is an abundant number, since it is smaller than the sum of its proper divisors (1072181934).

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

865899666 is a wasteful number, since it uses less digits than its factorization.

865899666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115511 (or 115505 counting only the distinct ones).

The product of its digits is 33592320, while the sum is 63.

The square root of 865899666 is about 29426.1731456878. The cubic root of 865899666 is about 953.1381599846.

The spelling of 865899666 in words is "eight hundred sixty-five million, eight hundred ninety-nine thousand, six hundred sixty-six".