625409 has 2 divisors, whose sum is σ = 625410. Its totient is φ = 625408.

The previous prime is 625397. The next prime is 625451. The reversal of 625409 is 904526.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 442225 + 183184 = 665^2 + 428^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-625409 is a prime.

It is a super-2 number, since 2×625409² = 782272834562, which contains 22 as substring.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 625409.

It is not a weakly prime, because it can be changed into another prime (625489) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 312704 + 312705.

It is an arithmetic number, because the mean of its divisors is an integer number (312705).

2⁶²⁵⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

625409 is a deficient number, since it is larger than the sum of its proper divisors (1).

625409 is an equidigital number, since it uses as much as digits as its factorization.

625409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 625409 is about 790.8280470494. The cubic root of 625409 is about 85.5174434048.

The spelling of 625409 in words is "six hundred twenty-five thousand, four hundred nine".