723903921 has 24 divisors (see below), whose sum is σ = 1133273960. Its totient is φ = 442630656.

The previous prime is 723903907. The next prime is 723903923. The reversal of 723903921 is 129309327.

It can be written as a sum of positive squares in 4 ways, for example, as 9090225 + 714813696 = 3015^2 + 26736^2 .

It is not a de Polignac number, because 723903921 - 2⁷ = 723903793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (723903923) 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, 1336 + ... + 38073.

Almost surely, 2^723903921 is an apocalyptic number.

It is an amenable number.

723903921 is a deficient number, since it is larger than the sum of its proper divisors (409370039).

723903921 is a wasteful number, since it uses less digits than its factorization.

723903921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39585 (or 39582 counting only the distinct ones).

The product of its (nonzero) digits is 20412, while the sum is 36.

The square root of 723903921 is about 26905.4626609542. The cubic root of 723903921 is about 897.8979423635.

The spelling of 723903921 in words is "seven hundred twenty-three million, nine hundred three thousand, nine hundred twenty-one".