25553516909 has 2 divisors, whose sum is σ = 25553516910. Its totient is φ = 25553516908.

The previous prime is 25553516899. The next prime is 25553516983. The reversal of 25553516909 is 90961535552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24776334025 + 777182884 = 157405^2 + 27878^2 .

It is a cyclic number.

It is not a de Polignac number, because 25553516909 - 2²⁴ = 25536739693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25553519909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12776758454 + 12776758455.

It is an arithmetic number, because the mean of its divisors is an integer number (12776758455).

Almost surely, 2^25553516909 is an apocalyptic number.

It is an amenable number.

25553516909 is a deficient number, since it is larger than the sum of its proper divisors (1).

25553516909 is an equidigital number, since it uses as much as digits as its factorization.

25553516909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1822500, while the sum is 50.

The spelling of 25553516909 in words is "twenty-five billion, five hundred fifty-three million, five hundred sixteen thousand, nine hundred nine".