666820620 has 48 divisors (see below), whose sum is σ = 2074554720. Its totient is φ = 177818688.

The previous prime is 666820607. The next prime is 666820639. The reversal of 666820620 is 26028666.

666820620 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 616887 + ... + 617966.

It is an arithmetic number, because the mean of its divisors is an integer number (43219890).

Almost surely, 2^666820620 is an apocalyptic number.

666820620 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

666820620 is an abundant number, since it is smaller than the sum of its proper divisors (1407734100).

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

666820620 is a wasteful number, since it uses less digits than its factorization.

666820620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1234871 (or 1234863 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 666820620 is about 25822.8700960989. The cubic root of 666820620 is about 873.6477048729.

The spelling of 666820620 in words is "six hundred sixty-six million, eight hundred twenty thousand, six hundred twenty".