721657742 has 16 divisors (see below), whose sum is σ = 1203361152. Its totient is φ = 322328160.

The previous prime is 721657709. The next prime is 721657757. The reversal of 721657742 is 247756127.

It is a self number, because there is not a number n which added to its sum of digits gives 721657742.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 446873 + ... + 448484.

It is an arithmetic number, because the mean of its divisors is an integer number (75210072).

Almost surely, 2^721657742 is an apocalyptic number.

721657742 is a deficient number, since it is larger than the sum of its proper divisors (481703410).

721657742 is a wasteful number, since it uses less digits than its factorization.

721657742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 895403.

The product of its digits is 164640, while the sum is 41.

The square root of 721657742 is about 26863.6881682319. The cubic root of 721657742 is about 896.9682936245.

The spelling of 721657742 in words is "seven hundred twenty-one million, six hundred fifty-seven thousand, seven hundred forty-two".