625518989 has 2 divisors, whose sum is σ = 625518990. Its totient is φ = 625518988.

The previous prime is 625518977. The next prime is 625518991. The reversal of 625518989 is 989815526.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 568440964 + 57078025 = 23842^2 + 7555^2 .

It is a cyclic number.

It is not a de Polignac number, because 625518989 - 2⁴ = 625518973 is a prime.

It is a Sophie Germain prime.

Together with 625518991, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 625518989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (625517989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 312759494 + 312759495.

It is an arithmetic number, because the mean of its divisors is an integer number (312759495).

Almost surely, 2^625518989 is an apocalyptic number.

It is an amenable number.

625518989 is a deficient number, since it is larger than the sum of its proper divisors (1).

625518989 is an equidigital number, since it uses as much as digits as its factorization.

625518989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1555200, while the sum is 53.

The square root of 625518989 is about 25010.3776260975. The cubic root of 625518989 is about 855.2245635187.

The spelling of 625518989 in words is "six hundred twenty-five million, five hundred eighteen thousand, nine hundred eighty-nine".