2565551 has 4 divisors (see below), whose sum is σ = 2700600. Its totient is φ = 2430504.

The previous prime is 2565463. The next prime is 2565559. The reversal of 2565551 is 1555652.

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

It is a cyclic number.

It is not a de Polignac number, because 2565551 - 2¹⁸ = 2303407 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2565559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67496 + ... + 67533.

It is an arithmetic number, because the mean of its divisors is an integer number (675150).

2^2565551 is an apocalyptic number.

2565551 is a deficient number, since it is larger than the sum of its proper divisors (135049).

2565551 is a wasteful number, since it uses less digits than its factorization.

2565551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135048.

The product of its digits is 7500, while the sum is 29.

The square root of 2565551 is about 1601.7337481617. The cubic root of 2565551 is about 136.8968801507.

The spelling of 2565551 in words is "two million, five hundred sixty-five thousand, five hundred fifty-one".