721652705 has 16 divisors (see below), whose sum is σ = 872785344. Its totient is φ = 572806080.

The previous prime is 721652693. The next prime is 721652731. The reversal of 721652705 is 507256127.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-721652705 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 417974 + ... + 419696.

It is an arithmetic number, because the mean of its divisors is an integer number (54549084).

Almost surely, 2^721652705 is an apocalyptic number.

It is an amenable number.

721652705 is a deficient number, since it is larger than the sum of its proper divisors (151132639).

721652705 is a wasteful number, since it uses less digits than its factorization.

721652705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2336.

The product of its (nonzero) digits is 29400, while the sum is 35.

The square root of 721652705 is about 26863.5944169800. The cubic root of 721652705 is about 896.9662067443.

The spelling of 721652705 in words is "seven hundred twenty-one million, six hundred fifty-two thousand, seven hundred five".