625561 has 4 divisors (see below), whose sum is σ = 627300. Its totient is φ = 623824.

The previous prime is 625543. The next prime is 625589. The reversal of 625561 is 165526.

625561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 165526 = 2 ⋅82763.

It can be written as a sum of positive squares in 2 ways, for example, as 577600 + 47961 = 760^2 + 219^2 .

It is a cyclic number.

It is not a de Polignac number, because 625561 - 2⁵ = 625529 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (625591) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106 + ... + 1123.

It is an arithmetic number, because the mean of its divisors is an integer number (156825).

2⁶²⁵⁵⁶¹ is an apocalyptic number.

It is an amenable number.

625561 is a deficient number, since it is larger than the sum of its proper divisors (1739).

625561 is a wasteful number, since it uses less digits than its factorization.

625561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1738.

The product of its digits is 1800, while the sum is 25.

The square root of 625561 is about 790.9241430125. The cubic root of 625561 is about 85.5243709239.

The spelling of 625561 in words is "six hundred twenty-five thousand, five hundred sixty-one".