2561464561 has 2 divisors, whose sum is σ = 2561464562. Its totient is φ = 2561464560.

The previous prime is 2561464531. The next prime is 2561464573. The reversal of 2561464561 is 1654641652.

2561464561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2465718336 + 95746225 = 49656^2 + 9785^2 .

It is a cyclic number.

It is not a de Polignac number, because 2561464561 - 2²³ = 2553075953 is a prime.

It is a super-2 number, since 2×2561464561² = 13122201394517845442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2561464531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1280732280 + 1280732281.

It is an arithmetic number, because the mean of its divisors is an integer number (1280732281).

Almost surely, 2^2561464561 is an apocalyptic number.

It is an amenable number.

2561464561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2561464561 is an equidigital number, since it uses as much as digits as its factorization.

2561464561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 172800, while the sum is 40.

The square root of 2561464561 is about 50610.9134574748. The cubic root of 2561464561 is about 1368.2415788681.

The spelling of 2561464561 in words is "two billion, five hundred sixty-one million, four hundred sixty-four thousand, five hundred sixty-one".