625394681 has 2 divisors, whose sum is σ = 625394682. Its totient is φ = 625394680.

The previous prime is 625394669. The next prime is 625394711. The reversal of 625394681 is 186493526.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 592435600 + 32959081 = 24340^2 + 5741^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-625394681 is a prime.

It is a super-2 number, since 2×625394681² = 782237014046183522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is equal to p_32579675 and since 625394681 and 32579675 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (625394621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 312697340 + 312697341.

It is an arithmetic number, because the mean of its divisors is an integer number (312697341).

Almost surely, 2^625394681 is an apocalyptic number.

It is an amenable number.

625394681 is a deficient number, since it is larger than the sum of its proper divisors (1).

625394681 is an equidigital number, since it uses as much as digits as its factorization.

625394681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 311040, while the sum is 44.

The square root of 625394681 is about 25007.8923742086. The cubic root of 625394681 is about 855.1679074726.

The spelling of 625394681 in words is "six hundred twenty-five million, three hundred ninety-four thousand, six hundred eighty-one".