646215788 has 6 divisors (see below), whose sum is σ = 1130877636. Its totient is φ = 323107892.

The previous prime is 646215763. The next prime is 646215809. The reversal of 646215788 is 887512646.

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 as a sum of consecutive naturals, namely, 80776970 + ... + 80776977.

It is an arithmetic number, because the mean of its divisors is an integer number (188479606).

Almost surely, 2^646215788 is an apocalyptic number.

It is an amenable number.

646215788 is a deficient number, since it is larger than the sum of its proper divisors (484661848).

646215788 is a wasteful number, since it uses less digits than its factorization.

646215788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161553951 (or 161553949 counting only the distinct ones).

The product of its digits is 645120, while the sum is 47.

The square root of 646215788 is about 25420.7747324900. The cubic root of 646215788 is about 864.5547902163.

The spelling of 646215788 in words is "six hundred forty-six million, two hundred fifteen thousand, seven hundred eighty-eight".