656816 has 10 divisors (see below), whose sum is σ = 1272612. Its totient is φ = 328400.

The previous prime is 656809. The next prime is 656819. The reversal of 656816 is 618656.

It is a super-4 number, since 4×656816⁴ (a number of 24 digits) contains 4444 as substring.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (656819) by changing a digit.

656816 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20510 + ... + 20541.

2⁶⁵⁶⁸¹⁶ is an apocalyptic number.

It is an amenable number.

656816 is a deficient number, since it is larger than the sum of its proper divisors (615796).

656816 is a wasteful number, since it uses less digits than its factorization.

656816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41059 (or 41053 counting only the distinct ones).

The product of its digits is 8640, while the sum is 32.

The square root of 656816 is about 810.4418547928. The cubic root of 656816 is about 86.9256421949.

The spelling of 656816 in words is "six hundred fifty-six thousand, eight hundred sixteen".