721916951 has 24 divisors (see below), whose sum is σ = 935999280. Its totient is φ = 551722752.

The previous prime is 721916927. The next prime is 721916963. The reversal of 721916951 is 159619127.

It is not a de Polignac number, because 721916951 - 2¹⁸ = 721654807 is a prime.

It is a super-2 number, since 2×721916951² = 1042328168282272802, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 721916899 and 721916908.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721912951) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6980 + ... + 38633.

It is an arithmetic number, because the mean of its divisors is an integer number (38999970).

Almost surely, 2^721916951 is an apocalyptic number.

721916951 is a deficient number, since it is larger than the sum of its proper divisors (214082329).

721916951 is a wasteful number, since it uses less digits than its factorization.

721916951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45663 (or 45656 counting only the distinct ones).

The product of its digits is 34020, while the sum is 41.

The square root of 721916951 is about 26868.5122587761. The cubic root of 721916951 is about 897.0756734388.

The spelling of 721916951 in words is "seven hundred twenty-one million, nine hundred sixteen thousand, nine hundred fifty-one".