2657561 has 2 divisors, whose sum is σ = 2657562. Its totient is φ = 2657560.

The previous prime is 2657533. The next prime is 2657563. The reversal of 2657561 is 1657562.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2343961 + 313600 = 1531^2 + 560^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2657561 is a prime.

Together with 2657563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2657563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1328780 + 1328781.

It is an arithmetic number, because the mean of its divisors is an integer number (1328781).

2^2657561 is an apocalyptic number.

It is an amenable number.

2657561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2657561 is an equidigital number, since it uses as much as digits as its factorization.

2657561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12600, while the sum is 32.

The square root of 2657561 is about 1630.2027481267. The cubic root of 2657561 is about 138.5142369600.

Subtracting from 2657561 its reverse (1657562), we obtain a palindrome (999999).

The spelling of 2657561 in words is "two million, six hundred fifty-seven thousand, five hundred sixty-one".