2661563 has 4 divisors (see below), whose sum is σ = 2718240. Its totient is φ = 2604888.

The previous prime is 2661557. The next prime is 2661569. The reversal of 2661563 is 3651662.

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

It is an interprime number because it is at equal distance from previous prime (2661557) and next prime (2661569).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2661563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2661569) 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, 28268 + ... + 28361.

It is an arithmetic number, because the mean of its divisors is an integer number (679560).

2^2661563 is an apocalyptic number.

2661563 is a deficient number, since it is larger than the sum of its proper divisors (56677).

2661563 is an equidigital number, since it uses as much as digits as its factorization.

2661563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56676.

The product of its digits is 6480, while the sum is 29.

The square root of 2661563 is about 1631.4297410554. The cubic root of 2661563 is about 138.5837312511.

Subtracting 2661563 from its reverse (3651662), we obtain a palindrome (990099).

The spelling of 2661563 in words is "two million, six hundred sixty-one thousand, five hundred sixty-three".