721525 has 36 divisors (see below), whose sum is σ = 1130880. Its totient is φ = 453600.

The previous prime is 721499. The next prime is 721529. The reversal of 721525 is 525127.

It is not a de Polignac number, because 721525 - 2⁷ = 721397 is a prime.

721525 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 721496 and 721505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721529) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 23260 + ... + 23290.

2⁷²¹⁵²⁵ is an apocalyptic number.

It is an amenable number.

721525 is a deficient number, since it is larger than the sum of its proper divisors (409355).

721525 is a wasteful number, since it uses less digits than its factorization.

721525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74 (or 62 counting only the distinct ones).

The product of its digits is 700, while the sum is 22.

The square root of 721525 is about 849.4262769658. The cubic root of 721525 is about 89.6913294022.

The spelling of 721525 in words is "seven hundred twenty-one thousand, five hundred twenty-five".