665868814 has 32 divisors (see below), whose sum is σ = 1138281984. Its totient is φ = 289803360.

The previous prime is 665868799. The next prime is 665868817. The reversal of 665868814 is 418868566.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665868817) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34617 + ... + 50299.

It is an arithmetic number, because the mean of its divisors is an integer number (35571312).

Almost surely, 2^665868814 is an apocalyptic number.

665868814 is a deficient number, since it is larger than the sum of its proper divisors (472413170).

665868814 is a wasteful number, since it uses less digits than its factorization.

665868814 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15792.

The product of its digits is 2211840, while the sum is 52.

The square root of 665868814 is about 25804.4339988305. The cubic root of 665868814 is about 873.2318313686.

The spelling of 665868814 in words is "six hundred sixty-five million, eight hundred sixty-eight thousand, eight hundred fourteen".