2561681047477 has 2 divisors, whose sum is σ = 2561681047478. Its totient is φ = 2561681047476.

The previous prime is 2561681047439. The next prime is 2561681047537. The reversal of 2561681047477 is 7747401861652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1655007633841 + 906673413636 = 1286471^2 + 952194^2 .

It is a cyclic number.

It is not a de Polignac number, because 2561681047477 - 2¹⁹ = 2561680523189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2561681047417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1280840523738 + 1280840523739.

It is an arithmetic number, because the mean of its divisors is an integer number (1280840523739).

Almost surely, 2^{2561681047477} is an apocalyptic number.

It is an amenable number.

2561681047477 is a deficient number, since it is larger than the sum of its proper divisors (1).

2561681047477 is an equidigital number, since it uses as much as digits as its factorization.

2561681047477 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15805440, while the sum is 58.

The spelling of 2561681047477 in words is "two trillion, five hundred sixty-one billion, six hundred eighty-one million, forty-seven thousand, four hundred seventy-seven".