25511513309 has 2 divisors, whose sum is σ = 25511513310. Its totient is φ = 25511513308.

The previous prime is 25511513299. The next prime is 25511513317. The reversal of 25511513309 is 90331511552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22081068409 + 3430444900 = 148597^2 + 58570^2 .

It is a cyclic number.

It is not a de Polignac number, because 25511513309 - 2²⁴ = 25494736093 is a prime.

It is a super-2 number, since 2×25511513309² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25511518309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12755756654 + 12755756655.

It is an arithmetic number, because the mean of its divisors is an integer number (12755756655).

Almost surely, 2^25511513309 is an apocalyptic number.

It is an amenable number.

25511513309 is a deficient number, since it is larger than the sum of its proper divisors (1).

25511513309 is an equidigital number, since it uses as much as digits as its factorization.

25511513309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20250, while the sum is 35.

The spelling of 25511513309 in words is "twenty-five billion, five hundred eleven million, five hundred thirteen thousand, three hundred nine".