721675656 has 80 divisors (see below), whose sum is σ = 2176874700. Its totient is φ = 222051456.

The previous prime is 721675631. The next prime is 721675657. The reversal of 721675656 is 656576127.

721675656 is a `hidden beast` number, since 7 + 21 + 67 + 565 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 693479556 + 28196100 = 26334^2 + 5310^2 .

It is not an unprimeable number, because it can be changed into a prime (721675657) 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 19 ways as a sum of consecutive naturals, for example, 34411 + ... + 51258.

Almost surely, 2^721675656 is an apocalyptic number.

It is an amenable number.

721675656 is an abundant number, since it is smaller than the sum of its proper divisors (1455199044).

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

721675656 is a wasteful number, since it uses less digits than its factorization.

721675656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85700 (or 85687 counting only the distinct ones).

The product of its digits is 529200, while the sum is 45.

The square root of 721675656 is about 26864.0215902236. The cubic root of 721675656 is about 896.9757154979.

The spelling of 721675656 in words is "seven hundred twenty-one million, six hundred seventy-five thousand, six hundred fifty-six".