721404023 has 4 divisors (see below), whose sum is σ = 726594120. Its totient is φ = 716213928.

The previous prime is 721403983. The next prime is 721404049. The reversal of 721404023 is 320404127.

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 721404023 - 2¹⁸ = 721141879 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 721404023.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721404823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2594840 + ... + 2595117.

It is an arithmetic number, because the mean of its divisors is an integer number (181648530).

Almost surely, 2^721404023 is an apocalyptic number.

721404023 is a deficient number, since it is larger than the sum of its proper divisors (5190097).

721404023 is a wasteful number, since it uses less digits than its factorization.

721404023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5190096.

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 721404023 is about 26858.9654119439. The cubic root of 721404023 is about 896.8631631908.

The spelling of 721404023 in words is "seven hundred twenty-one million, four hundred four thousand, twenty-three".