25647022081 has 4 divisors (see below), whose sum is σ = 26130928212. Its totient is φ = 25163115952.

The previous prime is 25647022019. The next prime is 25647022109. The reversal of 25647022081 is 18022074652.

It is a happy number.

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 20857136400 + 4789885681 = 144420^2 + 69209^2 .

It is a cyclic number.

It is not a de Polignac number, because 25647022081 - 2¹¹ = 25647020033 is a prime.

It is a super-2 number, since 2×25647022081² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 25647022081.

It is not an unprimeable number, because it can be changed into a prime (25647022381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 241952986 + ... + 241953091.

It is an arithmetic number, because the mean of its divisors is an integer number (6532732053).

Almost surely, 2^25647022081 is an apocalyptic number.

It is an amenable number.

25647022081 is a deficient number, since it is larger than the sum of its proper divisors (483906131).

25647022081 is an equidigital number, since it uses as much as digits as its factorization.

25647022081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 483906130.

The product of its (nonzero) digits is 53760, while the sum is 37.

The spelling of 25647022081 in words is "twenty-five billion, six hundred forty-seven million, twenty-two thousand, eighty-one".