625609 has 2 divisors, whose sum is σ = 625610. Its totient is φ = 625608.

The previous prime is 625591. The next prime is 625621. The reversal of 625609 is 906526.

625609 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 558009 + 67600 = 747^2 + 260^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-625609 is a prime.

It is not a weakly prime, because it can be changed into another prime (625699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 312804 + 312805.

It is an arithmetic number, because the mean of its divisors is an integer number (312805).

2⁶²⁵⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

625609 is a deficient number, since it is larger than the sum of its proper divisors (1).

625609 is an equidigital number, since it uses as much as digits as its factorization.

625609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 625609 is about 790.9544866805. The cubic root of 625609 is about 85.5265583284.

Adding to 625609 its product of nonzero digits (3240), we get a square (628849 = 793²).

It can be divided in two parts, 62 and 5609, that added together give a triangular number (5671 = T₁₀₆).

The spelling of 625609 in words is "six hundred twenty-five thousand, six hundred nine".