25561218763 has 2 divisors, whose sum is σ = 25561218764. Its totient is φ = 25561218762.

The previous prime is 25561218703. The next prime is 25561218779. The reversal of 25561218763 is 36781216552.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25561218763 is a prime.

It is not a weakly prime, because it can be changed into another prime (25561218703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12780609381 + 12780609382.

It is an arithmetic number, because the mean of its divisors is an integer number (12780609382).

Almost surely, 2^25561218763 is an apocalyptic number.

25561218763 is a deficient number, since it is larger than the sum of its proper divisors (1).

25561218763 is an equidigital number, since it uses as much as digits as its factorization.

25561218763 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 604800, while the sum is 46.

The spelling of 25561218763 in words is "twenty-five billion, five hundred sixty-one million, two hundred eighteen thousand, seven hundred sixty-three".