656640338 has 8 divisors (see below), whose sum is σ = 1008984060. Its totient is φ = 320312320.

The previous prime is 656640331. The next prime is 656640343. The reversal of 656640338 is 833046656.

It can be written as a sum of positive squares in 2 ways, for example, as 485893849 + 170746489 = 22043^2 + 13067^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 656640295 and 656640304.

It is not an unprimeable number, because it can be changed into a prime (656640331) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 4003823 + ... + 4003986.

Almost surely, 2^656640338 is an apocalyptic number.

656640338 is a deficient number, since it is larger than the sum of its proper divisors (352343722).

656640338 is a wasteful number, since it uses less digits than its factorization.

656640338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8007852.

The product of its (nonzero) digits is 311040, while the sum is 41.

The square root of 656640338 is about 25624.9943999994. The cubic root of 656640338 is about 869.1789223472.

The spelling of 656640338 in words is "six hundred fifty-six million, six hundred forty thousand, three hundred thirty-eight".