2567661 has 4 divisors (see below), whose sum is σ = 3423552. Its totient is φ = 1711772.

The previous prime is 2567647. The next prime is 2567671. The reversal of 2567661 is 1667652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2567661 - 2⁷ = 2567533 is a prime.

It is a D-number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2567611) 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, 427941 + ... + 427946.

It is an arithmetic number, because the mean of its divisors is an integer number (855888).

2^2567661 is an apocalyptic number.

It is an amenable number.

2567661 is a deficient number, since it is larger than the sum of its proper divisors (855891).

2567661 is an equidigital number, since it uses as much as digits as its factorization.

2567661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 855890.

The product of its digits is 15120, while the sum is 33.

The square root of 2567661 is about 1602.3922740702. The cubic root of 2567661 is about 136.9343994809.

Subtracting from 2567661 its reverse (1667652), we obtain a palindrome (900009).

The spelling of 2567661 in words is "two million, five hundred sixty-seven thousand, six hundred sixty-one".