2561794641 has 48 divisors (see below), whose sum is σ = 4458276480. Its totient is φ = 1424174400.

The previous prime is 2561794639. The next prime is 2561794657. The reversal of 2561794641 is 1464971652.

2561794641 is a `hidden beast` number, since 2 + 561 + 7 + 9 + 46 + 41 = 666.

It is not a de Polignac number, because 2561794641 - 2¹ = 2561794639 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2561794241) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 253791 + ... + 263691.

It is an arithmetic number, because the mean of its divisors is an integer number (92880760).

Almost surely, 2^2561794641 is an apocalyptic number.

2561794641 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2561794641 is a deficient number, since it is larger than the sum of its proper divisors (1896481839).

2561794641 is an equidigital number, since it uses as much as digits as its factorization.

2561794641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9991 (or 9948 counting only the distinct ones).

The product of its digits is 362880, while the sum is 45.

The square root of 2561794641 is about 50614.1743091794. The cubic root of 2561794641 is about 1368.3003486033.

The spelling of 2561794641 in words is "two billion, five hundred sixty-one million, seven hundred ninety-four thousand, six hundred forty-one".