25563565897 has 2 divisors, whose sum is σ = 25563565898. Its totient is φ = 25563565896.

The previous prime is 25563565883. The next prime is 25563565933. The reversal of 25563565897 is 79856536552.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25550104336 + 13461561 = 159844^2 + 3669^2 .

It is a cyclic number.

It is not a de Polignac number, because 25563565897 - 2¹¹ = 25563563849 is a prime.

It is a super-2 number, since 2×25563565897² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25563565847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12781782948 + 12781782949.

It is an arithmetic number, because the mean of its divisors is an integer number (12781782949).

Almost surely, 2^25563565897 is an apocalyptic number.

It is an amenable number.

25563565897 is a deficient number, since it is larger than the sum of its proper divisors (1).

25563565897 is an equidigital number, since it uses as much as digits as its factorization.

25563565897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 68040000, while the sum is 61.

The spelling of 25563565897 in words is "twenty-five billion, five hundred sixty-three million, five hundred sixty-five thousand, eight hundred ninety-seven".