646122388 has 12 divisors (see below), whose sum is σ = 1130894100. Its totient is φ = 323009792.

The previous prime is 646122377. The next prime is 646122391. The reversal of 646122388 is 883221646.

It can be written as a sum of positive squares in 2 ways, for example, as 150258564 + 495863824 = 12258^2 + 22268^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 646122388.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36420 + ... + 51172.

It is an arithmetic number, because the mean of its divisors is an integer number (94241175).

Almost surely, 2^646122388 is an apocalyptic number.

It is an amenable number.

646122388 is a deficient number, since it is larger than the sum of its proper divisors (484771712).

646122388 is a wasteful number, since it uses less digits than its factorization.

646122388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25706 (or 25704 counting only the distinct ones).

The product of its digits is 110592, while the sum is 40.

The square root of 646122388 is about 25418.9375859810. The cubic root of 646122388 is about 864.5131357568.

The spelling of 646122388 in words is "six hundred forty-six million, one hundred twenty-two thousand, three hundred eighty-eight".