65665816 has 16 divisors (see below), whose sum is σ = 125987400. Its totient is φ = 32069184.

The previous prime is 65665811. The next prime is 65665819. The reversal of 65665816 is 61856656.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65665811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95101 + ... + 95788.

Almost surely, 2^65665816 is an apocalyptic number.

It is an amenable number.

65665816 is a deficient number, since it is larger than the sum of its proper divisors (60321584).

65665816 is a wasteful number, since it uses less digits than its factorization.

65665816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190938 (or 190934 counting only the distinct ones).

The product of its digits is 259200, while the sum is 43.

The square root of 65665816 is about 8103.4446996324. Note that the first 3 decimals coincide. The cubic root of 65665816 is about 403.4407679259.

The spelling of 65665816 in words is "sixty-five million, six hundred sixty-five thousand, eight hundred sixteen".