2644632561 has 4 divisors (see below), whose sum is σ = 3526176752. Its totient is φ = 1763088372.

The previous prime is 2644632517. The next prime is 2644632593. The reversal of 2644632561 is 1652364462.

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 not a de Polignac number, because 2644632561 - 2²² = 2640438257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2644632511) 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, 440772091 + ... + 440772096.

It is an arithmetic number, because the mean of its divisors is an integer number (881544188).

Almost surely, 2^2644632561 is an apocalyptic number.

It is an amenable number.

2644632561 is a deficient number, since it is larger than the sum of its proper divisors (881544191).

2644632561 is an equidigital number, since it uses as much as digits as its factorization.

2644632561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 881544190.

The product of its digits is 207360, while the sum is 39.

The square root of 2644632561 is about 51425.9911037211. The cubic root of 2644632561 is about 1382.8925816180.

The spelling of 2644632561 in words is "two billion, six hundred forty-four million, six hundred thirty-two thousand, five hundred sixty-one".