656993646 has 64 divisors (see below), whose sum is σ = 1499562240. Its totient is φ = 213101280.

The previous prime is 656993641. The next prime is 656993663. The reversal of 656993646 is 646399656.

It is a happy number.

656993646 is a `hidden beast` number, since 6 + 569 + 9 + 36 + 46 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 656993592 and 656993601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656993641) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 1214136 + ... + 1214676.

It is an arithmetic number, because the mean of its divisors is an integer number (23430660).

Almost surely, 2^656993646 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 656993646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (749781120).

656993646 is an abundant number, since it is smaller than the sum of its proper divisors (842568594).

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

656993646 is a wasteful number, since it uses less digits than its factorization.

656993646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1118 (or 1112 counting only the distinct ones).

The product of its digits is 6298560, while the sum is 54.

The square root of 656993646 is about 25631.8872890780. The cubic root of 656993646 is about 869.3347828128.

The spelling of 656993646 in words is "six hundred fifty-six million, nine hundred ninety-three thousand, six hundred forty-six".