25887252817 has 2 divisors, whose sum is σ = 25887252818. Its totient is φ = 25887252816.

The previous prime is 25887252803. The next prime is 25887252821. The reversal of 25887252817 is 71825278852.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25802318161 + 84934656 = 160631^2 + 9216^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25887252817 is a prime.

It is a super-2 number, since 2×25887252817² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25887252847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12943626408 + 12943626409.

It is an arithmetic number, because the mean of its divisors is an integer number (12943626409).

Almost surely, 2^25887252817 is an apocalyptic number.

It is an amenable number.

25887252817 is a deficient number, since it is larger than the sum of its proper divisors (1).

25887252817 is an equidigital number, since it uses as much as digits as its factorization.

25887252817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5017600, while the sum is 55.

The spelling of 25887252817 in words is "twenty-five billion, eight hundred eighty-seven million, two hundred fifty-two thousand, eight hundred seventeen".