721383975 has 120 divisors (see below), whose sum is σ = 1464090320. Its totient is φ = 348986880.

The previous prime is 721383941. The next prime is 721383979. The reversal of 721383975 is 579383127.

It is a happy number.

It is not a de Polignac number, because 721383975 - 2⁶ = 721383911 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 721383975.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721383979) 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 119 ways as a sum of consecutive naturals, for example, 1763571 + ... + 1763979.

Almost surely, 2^721383975 is an apocalyptic number.

721383975 is a gapful number since it is divisible by the number (75) formed by its first and last digit.

721383975 is an abundant number, since it is smaller than the sum of its proper divisors (742706345).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

721383975 is a wasteful number, since it uses less digits than its factorization.

721383975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 511 (or 497 counting only the distinct ones).

The product of its digits is 317520, while the sum is 45.

The square root of 721383975 is about 26858.5922006348. The cubic root of 721383975 is about 896.8548550959.

The spelling of 721383975 in words is "seven hundred twenty-one million, three hundred eighty-three thousand, nine hundred seventy-five".