625721 has 4 divisors (see below), whose sum is σ = 627444. Its totient is φ = 624000.

The previous prime is 625699. The next prime is 625763. The reversal of 625721 is 127526.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 55696 + 570025 = 236^2 + 755^2 .

It is a cyclic number.

It is not a de Polignac number, because 625721 - 2⁶ = 625657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (625621) 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, 80 + ... + 1121.

It is an arithmetic number, because the mean of its divisors is an integer number (156861).

2⁶²⁵⁷²¹ is an apocalyptic number.

It is an amenable number.

625721 is a deficient number, since it is larger than the sum of its proper divisors (1723).

625721 is a wasteful number, since it uses less digits than its factorization.

625721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1722.

The product of its digits is 840, while the sum is 23.

The square root of 625721 is about 791.0252840460. The cubic root of 625721 is about 85.5316618371.

The spelling of 625721 in words is "six hundred twenty-five thousand, seven hundred twenty-one".