756656640 has 400 divisors, whose sum is σ = 2807398440. Its totient is φ = 194641920.

The previous prime is 756656639. The next prime is 756656683. The reversal of 756656640 is 46656657.

It can be written as a sum of positive squares in 4 ways, for example, as 283855104 + 472801536 = 16848^2 + 21744^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 8501716 + ... + 8501804.

Almost surely, 2^756656640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 756656640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1403699220).

756656640 is an abundant number, since it is smaller than the sum of its proper divisors (2050741800).

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

756656640 is an equidigital number, since it uses as much as digits as its factorization.

756656640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165 (or 140 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 45.

The square root of 756656640 is about 27507.3924609368. The cubic root of 756656640 is about 911.2403646799.

The spelling of 756656640 in words is "seven hundred fifty-six million, six hundred fifty-six thousand, six hundred forty".