646887788646 has 32 divisors (see below), whose sum is σ = 1411426435968. Its totient is φ = 196021755840.

The previous prime is 646887788609. The next prime is 646887788669.

646887788646 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×646887788646² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

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, 3290746 + ... + 3481778.

It is an arithmetic number, because the mean of its divisors is an integer number (44107076124).

Almost surely, 2^646887788646 is an apocalyptic number.

646887788646 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

646887788646 is an abundant number, since it is smaller than the sum of its proper divisors (764538647322).

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

646887788646 is a wasteful number, since it uses less digits than its factorization.

646887788646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242356.

The product of its digits is 4161798144, while the sum is 78.

The spelling of 646887788646 in words is "six hundred forty-six billion, eight hundred eighty-seven million, seven hundred eighty-eight thousand, six hundred forty-six".