25522618565 has 4 divisors (see below), whose sum is σ = 30627142284. Its totient is φ = 20418094848.

The previous prime is 25522618549. The next prime is 25522618601. The reversal of 25522618565 is 56581622552.

It is a Cunningham number, because it is equal to 159758²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9187989316 + 16334629249 = 95854^2 + 127807^2 .

It is a cyclic number.

It is not a de Polignac number, because 25522618565 - 2⁴ = 25522618549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2552261852 + ... + 2552261861.

It is an arithmetic number, because the mean of its divisors is an integer number (7656785571).

Almost surely, 2^25522618565 is an apocalyptic number.

It is an amenable number.

25522618565 is a deficient number, since it is larger than the sum of its proper divisors (5104523719).

25522618565 is an equidigital number, since it uses as much as digits as its factorization.

25522618565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5104523718.

The product of its digits is 1440000, while the sum is 47.

The spelling of 25522618565 in words is "twenty-five billion, five hundred twenty-two million, six hundred eighteen thousand, five hundred sixty-five".