25448648781 has 4 divisors (see below), whose sum is σ = 33931531712. Its totient is φ = 16965765852.

The previous prime is 25448648779. The next prime is 25448648833. The reversal of 25448648781 is 18784684452.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 25448648781 - 2¹ = 25448648779 is a prime.

It is a super-2 number, since 2×25448648781² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25448648761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4241441461 + ... + 4241441466.

It is an arithmetic number, because the mean of its divisors is an integer number (8482882928).

Almost surely, 2^25448648781 is an apocalyptic number.

It is an amenable number.

25448648781 is a deficient number, since it is larger than the sum of its proper divisors (8482882931).

25448648781 is an equidigital number, since it uses as much as digits as its factorization.

25448648781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8482882930.

The product of its digits is 13762560, while the sum is 57.

The spelling of 25448648781 in words is "twenty-five billion, four hundred forty-eight million, six hundred forty-eight thousand, seven hundred eighty-one".