625681 has 9 divisors (see below), whose sum is σ = 734331. Its totient is φ = 531552.

The previous prime is 625663. The next prime is 625697. The reversal of 625681 is 186526.

The square root of 625681 is 791.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 11025 + 614656 = 105^2 + 784^2 .

It is not a de Polignac number, because 625681 - 2⁹ = 625169 is a prime.

It is a super-2 number, since 2×625681² = 782953427522, which contains 22 as substring.

It is a Duffinian number.

625681 is a Rhonda number in base 15.

Its product of digits (2880) is a multiple of the sum of its prime divisors (120).

It is not an unprimeable number, because it can be changed into a prime (625621) 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 in 8 ways as a sum of consecutive naturals, for example, 5481 + ... + 5593.

2⁶²⁵⁶⁸¹ is an apocalyptic number.

625681 is the 791-st square number.

625681 is the 396-th centered octagonal number.

It is an amenable number.

625681 is a deficient number, since it is larger than the sum of its proper divisors (108650).

625681 is an equidigital number, since it uses as much as digits as its factorization.

625681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240 (or 120 counting only the distinct ones).

The product of its digits is 2880, while the sum is 28.

The cubic root of 625681 is about 85.5298392253.

The spelling of 625681 in words is "six hundred twenty-five thousand, six hundred eighty-one".