721974943691 has 8 divisors (see below), whose sum is σ = 731963887200. Its totient is φ = 712027708480.

The previous prime is 721974943663. The next prime is 721974943757. The reversal of 721974943691 is 196349479127.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721974943691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721974943621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10392215 + ... + 10461456.

It is an arithmetic number, because the mean of its divisors is an integer number (91495485900).

Almost surely, 2^721974943691 is an apocalyptic number.

721974943691 is a deficient number, since it is larger than the sum of its proper divisors (9988943509).

721974943691 is a wasteful number, since it uses less digits than its factorization.

721974943691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20854149.

The product of its digits is 20575296, while the sum is 62.

The spelling of 721974943691 in words is "seven hundred twenty-one billion, nine hundred seventy-four million, nine hundred forty-three thousand, six hundred ninety-one".