7685665866 has 12 divisors (see below), whose sum is σ = 16652276082. Its totient is φ = 2561888616.

The previous prime is 7685665853. The next prime is 7685665873. The reversal of 7685665866 is 6685665867.

7685665866 is a `hidden beast` number, since 7 + 6 + 8 + 566 + 5 + 8 + 66 = 666.

It can be written as a sum of positive squares in only one way, i.e., 7441650225 + 244015641 = 86265^2 + 15621^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 213490701 + ... + 213490736.

Almost surely, 2^7685665866 is an apocalyptic number.

7685665866 is an abundant number, since it is smaller than the sum of its proper divisors (8966610216).

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

7685665866 is a wasteful number, since it uses less digits than its factorization.

7685665866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426981445 (or 426981442 counting only the distinct ones).

The product of its digits is 87091200, while the sum is 63.

The square root of 7685665866 is about 87667.9295181539. The cubic root of 7685665866 is about 1973.4547216981.

Subtracting from 7685665866 its reverse (6685665867), we obtain a palindrome (999999999).

The spelling of 7685665866 in words is "seven billion, six hundred eighty-five million, six hundred sixty-five thousand, eight hundred sixty-six".