25539908749 has 2 divisors, whose sum is σ = 25539908750. Its totient is φ = 25539908748.

The previous prime is 25539908743. The next prime is 25539908753. The reversal of 25539908749 is 94780993552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21824152900 + 3715755849 = 147730^2 + 60957^2 .

It is a cyclic number.

It is not a de Polignac number, because 25539908749 - 2⁵ = 25539908717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25539908743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12769954374 + 12769954375.

It is an arithmetic number, because the mean of its divisors is an integer number (12769954375).

Almost surely, 2^25539908749 is an apocalyptic number.

It is an amenable number.

25539908749 is a deficient number, since it is larger than the sum of its proper divisors (1).

25539908749 is an equidigital number, since it uses as much as digits as its factorization.

25539908749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24494400, while the sum is 61.

The spelling of 25539908749 in words is "twenty-five billion, five hundred thirty-nine million, nine hundred eight thousand, seven hundred forty-nine".