646564342020 has 48 divisors (see below), whose sum is σ = 1837400768448. Its totient is φ = 169843766400.

The previous prime is 646564341989. The next prime is 646564342037. The reversal of 646564342020 is 20243465646.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 80414431 + ... + 80422470.

It is an arithmetic number, because the mean of its divisors is an integer number (38279182676).

Almost surely, 2^646564342020 is an apocalyptic number.

646564342020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

646564342020 is an abundant number, since it is smaller than the sum of its proper divisors (1190836426428).

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

646564342020 is a wasteful number, since it uses less digits than its factorization.

646564342020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160836980 (or 160836978 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 42.

The spelling of 646564342020 in words is "six hundred forty-six billion, five hundred sixty-four million, three hundred forty-two thousand, twenty".