25503769661 has 2 divisors, whose sum is σ = 25503769662. Its totient is φ = 25503769660.

The previous prime is 25503769649. The next prime is 25503769723. The reversal of 25503769661 is 16696730552.

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., 23167884100 + 2335885561 = 152210^2 + 48331^2 .

It is a cyclic number.

It is not a de Polignac number, because 25503769661 - 2¹⁰ = 25503768637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25503763661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12751884830 + 12751884831.

It is an arithmetic number, because the mean of its divisors is an integer number (12751884831).

Almost surely, 2^25503769661 is an apocalyptic number.

It is an amenable number.

25503769661 is a deficient number, since it is larger than the sum of its proper divisors (1).

25503769661 is an equidigital number, since it uses as much as digits as its factorization.

25503769661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2041200, while the sum is 50.

The spelling of 25503769661 in words is "twenty-five billion, five hundred three million, seven hundred sixty-nine thousand, six hundred sixty-one".