2561557 has 4 divisors (see below), whose sum is σ = 2624076. Its totient is φ = 2499040.

The previous prime is 2561551. The next prime is 2561593. The reversal of 2561557 is 7551652.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 269361 + 2292196 = 519^2 + 1514^2 .

It is a cyclic number.

It is not a de Polignac number, because 2561557 - 2³ = 2561549 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561551) 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, 31198 + ... + 31279.

It is an arithmetic number, because the mean of its divisors is an integer number (656019).

2^2561557 is an apocalyptic number.

It is an amenable number.

2561557 is a deficient number, since it is larger than the sum of its proper divisors (62519).

2561557 is an equidigital number, since it uses as much as digits as its factorization.

2561557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62518.

The product of its digits is 10500, while the sum is 31.

The square root of 2561557 is about 1600.4864885403. The cubic root of 2561557 is about 136.8258037859.

The spelling of 2561557 in words is "two million, five hundred sixty-one thousand, five hundred fifty-seven".