721975 has 6 divisors (see below), whose sum is σ = 895280. Its totient is φ = 577560.

The previous prime is 721961. The next prime is 721979. The reversal of 721975 is 579127.

It is a de Polignac number, because none of the positive numbers 2^k-721975 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721979) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 14415 + ... + 14464.

2⁷²¹⁹⁷⁵ is an apocalyptic number.

721975 is a deficient number, since it is larger than the sum of its proper divisors (173305).

721975 is a wasteful number, since it uses less digits than its factorization.

721975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28889 (or 28884 counting only the distinct ones).

The product of its digits is 4410, while the sum is 31.

The square root of 721975 is about 849.6911203490. The cubic root of 721975 is about 89.7099717271.

The spelling of 721975 in words is "seven hundred twenty-one thousand, nine hundred seventy-five".