2561015777 has 2 divisors, whose sum is σ = 2561015778. Its totient is φ = 2561015776.

The previous prime is 2561015761. The next prime is 2561015867. The reversal of 2561015777 is 7775101652.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2280922081 + 280093696 = 47759^2 + 16736^2 .

It is a cyclic number.

It is not a de Polignac number, because 2561015777 - 2⁴ = 2561015761 is a prime.

It is not a weakly prime, because it can be changed into another prime (2561015747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1280507888 + 1280507889.

It is an arithmetic number, because the mean of its divisors is an integer number (1280507889).

Almost surely, 2^2561015777 is an apocalyptic number.

It is an amenable number.

2561015777 is a deficient number, since it is larger than the sum of its proper divisors (1).

2561015777 is an equidigital number, since it uses as much as digits as its factorization.

2561015777 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 102900, while the sum is 41.

The square root of 2561015777 is about 50606.4795950084. The cubic root of 2561015777 is about 1368.1616661490.

The spelling of 2561015777 in words is "two billion, five hundred sixty-one million, fifteen thousand, seven hundred seventy-seven".