25291575521 has 2 divisors, whose sum is σ = 25291575522. Its totient is φ = 25291575520.

The previous prime is 25291575503. The next prime is 25291575541. The reversal of 25291575521 is 12557519252.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23612624896 + 1678950625 = 153664^2 + 40975^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25291575521 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (25291575541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12645787760 + 12645787761.

It is an arithmetic number, because the mean of its divisors is an integer number (12645787761).

Almost surely, 2^25291575521 is an apocalyptic number.

It is an amenable number.

25291575521 is a deficient number, since it is larger than the sum of its proper divisors (1).

25291575521 is an equidigital number, since it uses as much as digits as its factorization.

25291575521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 315000, while the sum is 44.

The spelling of 25291575521 in words is "twenty-five billion, two hundred ninety-one million, five hundred seventy-five thousand, five hundred twenty-one".