665920836 has 36 divisors (see below), whose sum is σ = 1923772032. Its totient is φ = 190263024.

The previous prime is 665920807. The next prime is 665920859. The reversal of 665920836 is 638029566.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a junction number, because it is equal to n+sod(n) for n = 665920791 and 665920800.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1321020 + ... + 1321523.

It is an arithmetic number, because the mean of its divisors is an integer number (53438112).

Almost surely, 2^665920836 is an apocalyptic number.

It is an amenable number.

665920836 is an abundant number, since it is smaller than the sum of its proper divisors (1257851196).

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

665920836 is a wasteful number, since it uses less digits than its factorization.

665920836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2642560 (or 2642555 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The square root of 665920836 is about 25805.4419842017. The cubic root of 665920836 is about 873.2545716253.

It can be divided in two parts, 6659 and 20836, that added together give a triangular number (27495 = T₂₃₄).

The spelling of 665920836 in words is "six hundred sixty-five million, nine hundred twenty thousand, eight hundred thirty-six".