2561620625687 has 2 divisors, whose sum is σ = 2561620625688. Its totient is φ = 2561620625686.

The previous prime is 2561620625657. The next prime is 2561620625747. The reversal of 2561620625687 is 7865260261652.

It is a happy number.

2561620625687 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2561620625687 - 2²² = 2561616431383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2561620625657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1280810312843 + 1280810312844.

It is an arithmetic number, because the mean of its divisors is an integer number (1280810312844).

Almost surely, 2^{2561620625687} is an apocalyptic number.

2561620625687 is a deficient number, since it is larger than the sum of its proper divisors (1).

2561620625687 is an equidigital number, since it uses as much as digits as its factorization.

2561620625687 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14515200, while the sum is 56.

The spelling of 2561620625687 in words is "two trillion, five hundred sixty-one billion, six hundred twenty million, six hundred twenty-five thousand, six hundred eighty-seven".