725921 has 4 divisors (see below), whose sum is σ = 829632. Its totient is φ = 622212.

The previous prime is 725909. The next prime is 725929. The reversal of 725921 is 129527.

725921 is nontrivially palindromic in base 5.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 725921 - 2¹⁴ = 709537 is a prime.

It is a super-2 number, since 2×725921² = 1053922596482, which contains 22 as substring.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 725921.

It is not an unprimeable number, because it can be changed into a prime (725929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51845 + ... + 51858.

It is an arithmetic number, because the mean of its divisors is an integer number (207408).

2⁷²⁵⁹²¹ is an apocalyptic number.

It is an amenable number.

725921 is a deficient number, since it is larger than the sum of its proper divisors (103711).

725921 is a wasteful number, since it uses less digits than its factorization.

725921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103710.

The product of its digits is 1260, while the sum is 26.

The square root of 725921 is about 852.0099764674. The cubic root of 725921 is about 89.8731133739.

The spelling of 725921 in words is "seven hundred twenty-five thousand, nine hundred twenty-one".