25565504897 has 2 divisors, whose sum is σ = 25565504898. Its totient is φ = 25565504896.

The previous prime is 25565504869. The next prime is 25565504947. The reversal of 25565504897 is 79840556552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25303583041 + 261921856 = 159071^2 + 16184^2 .

It is a cyclic number.

It is not a de Polignac number, because 25565504897 - 2⁸ = 25565504641 is a prime.

It is a super-3 number, since 3×25565504897³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (25565554897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12782752448 + 12782752449.

It is an arithmetic number, because the mean of its divisors is an integer number (12782752449).

Almost surely, 2^25565504897 is an apocalyptic number.

It is an amenable number.

25565504897 is a deficient number, since it is larger than the sum of its proper divisors (1).

25565504897 is an equidigital number, since it uses as much as digits as its factorization.

25565504897 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120000, while the sum is 56.

The spelling of 25565504897 in words is "twenty-five billion, five hundred sixty-five million, five hundred four thousand, eight hundred ninety-seven".