731708640 has 480 divisors, whose sum is σ = 2873810016. Its totient is φ = 174182400.

The previous prime is 731708623. The next prime is 731708647. The reversal of 731708640 is 46807137.

731708640 is a `hidden beast` number, since 7 + 3 + 1 + 7 + 0 + 8 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 731708595 and 731708604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (731708647) 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 79 ways as a sum of consecutive naturals, for example, 7244590 + ... + 7244690.

Almost surely, 2^731708640 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 731708640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1436905008).

731708640 is an abundant number, since it is smaller than the sum of its proper divisors (2142101376).

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

731708640 is a wasteful number, since it uses less digits than its factorization.

731708640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184 (or 167 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 36.

The square root of 731708640 is about 27050.1134932924. The cubic root of 731708640 is about 901.1132889740.

It can be divided in two parts, 73170 and 8640, that added together give a triangular number (81810 = T₄₀₄).

The spelling of 731708640 in words is "seven hundred thirty-one million, seven hundred eight thousand, six hundred forty".