721891942791 has 8 divisors (see below), whose sum is σ = 962881349760. Its totient is φ = 481081915512.

The previous prime is 721891942781. The next prime is 721891942819. The reversal of 721891942791 is 197249198127.

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

It is not a de Polignac number, because 721891942791 - 2¹⁴ = 721891926407 is a prime.

It is a super-2 number, since 2×721891942791² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721891942781) 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, 44835531 + ... + 44851628.

It is an arithmetic number, because the mean of its divisors is an integer number (120360168720).

Almost surely, 2^721891942791 is an apocalyptic number.

721891942791 is a deficient number, since it is larger than the sum of its proper divisors (240989406969).

721891942791 is a wasteful number, since it uses less digits than its factorization.

721891942791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89689845.

The product of its digits is 4572288, while the sum is 60.

The spelling of 721891942791 in words is "seven hundred twenty-one billion, eight hundred ninety-one million, nine hundred forty-two thousand, seven hundred ninety-one".