721616735 has 32 divisors (see below), whose sum is σ = 1022585472. Its totient is φ = 478517760.

The previous prime is 721616723. The next prime is 721616737. The reversal of 721616735 is 537616127.

It is not a de Polignac number, because 721616735 - 2⁴ = 721616719 is a prime.

It is a super-4 number, since 4×721616735⁴ (a number of 37 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721616737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 222425 + ... + 225645.

It is an arithmetic number, because the mean of its divisors is an integer number (31955796).

Almost surely, 2^721616735 is an apocalyptic number.

721616735 is a deficient number, since it is larger than the sum of its proper divisors (300968737).

721616735 is a wasteful number, since it uses less digits than its factorization.

721616735 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3443.

The product of its digits is 52920, while the sum is 38.

The square root of 721616735 is about 26862.9249152061. The cubic root of 721616735 is about 896.9513037259.

The spelling of 721616735 in words is "seven hundred twenty-one million, six hundred sixteen thousand, seven hundred thirty-five".