2644620561 has 12 divisors (see below), whose sum is σ = 4167281040. Its totient is φ = 1602800280.

The previous prime is 2644620557. The next prime is 2644620607. The reversal of 2644620561 is 1650264462.

2644620561 is a `hidden beast` number, since 2 + 6 + 446 + 205 + 6 + 1 = 666.

It is not a de Polignac number, because 2644620561 - 2² = 2644620557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2644620161) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13356571 + ... + 13356768.

It is an arithmetic number, because the mean of its divisors is an integer number (347273420).

Almost surely, 2^2644620561 is an apocalyptic number.

It is an amenable number.

2644620561 is a deficient number, since it is larger than the sum of its proper divisors (1522660479).

2644620561 is a wasteful number, since it uses less digits than its factorization.

2644620561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26713356 (or 26713353 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The square root of 2644620561 is about 51425.8744310683. The cubic root of 2644620561 is about 1382.8904899934.

The spelling of 2644620561 in words is "two billion, six hundred forty-four million, six hundred twenty thousand, five hundred sixty-one".