668536836 has 96 divisors (see below), whose sum is σ = 1749952512. Its totient is φ = 196909440.

The previous prime is 668536801. The next prime is 668536853. The reversal of 668536836 is 638635866.

It is a hoax number, since the sum of its digits (51) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1221915 + ... + 1222461.

It is an arithmetic number, because the mean of its divisors is an integer number (18228672).

Almost surely, 2^668536836 is an apocalyptic number.

668536836 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 668536836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (874976256).

668536836 is an abundant number, since it is smaller than the sum of its proper divisors (1081415676).

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

668536836 is a wasteful number, since it uses less digits than its factorization.

668536836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 809 (or 807 counting only the distinct ones).

The product of its digits is 3732480, while the sum is 51.

The square root of 668536836 is about 25856.0792851507. The cubic root of 668536836 is about 874.3965737780.

The spelling of 668536836 in words is "six hundred sixty-eight million, five hundred thirty-six thousand, eight hundred thirty-six".