720723645 has 72 divisors (see below), whose sum is σ = 1312492896. Its totient is φ = 365633856.

The previous prime is 720723613. The next prime is 720723667. The reversal of 720723645 is 546327027.

It is a happy number.

720723645 is a `hidden beast` number, since 7 + 2 + 0 + 7 + 2 + 3 + 645 = 666.

It is not a de Polignac number, because 720723645 - 2⁵ = 720723613 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 6735682 + ... + 6735788.

It is an arithmetic number, because the mean of its divisors is an integer number (18229068).

Almost surely, 2^720723645 is an apocalyptic number.

It is an amenable number.

720723645 is a deficient number, since it is larger than the sum of its proper divisors (591769251).

720723645 is a wasteful number, since it uses less digits than its factorization.

720723645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279 (or 217 counting only the distinct ones).

The product of its (nonzero) digits is 70560, while the sum is 36.

The square root of 720723645 is about 26846.2966719807. The cubic root of 720723645 is about 896.5811215605.

The spelling of 720723645 in words is "seven hundred twenty million, seven hundred twenty-three thousand, six hundred forty-five".