721682611 has 4 divisors (see below), whose sum is σ = 777196672. Its totient is φ = 666168552.

The previous prime is 721682597. The next prime is 721682627. The reversal of 721682611 is 116286127.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 721682611 - 2⁷ = 721682483 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721682711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27757011 + ... + 27757036.

It is an arithmetic number, because the mean of its divisors is an integer number (194299168).

Almost surely, 2^721682611 is an apocalyptic number.

721682611 is a deficient number, since it is larger than the sum of its proper divisors (55514061).

721682611 is a wasteful number, since it uses less digits than its factorization.

721682611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55514060.

The product of its digits is 8064, while the sum is 34.

The square root of 721682611 is about 26864.1510381400. The cubic root of 721682611 is about 896.9785969613.

The spelling of 721682611 in words is "seven hundred twenty-one million, six hundred eighty-two thousand, six hundred eleven".