25806781123 has 4 divisors (see below), whose sum is σ = 25807228128. Its totient is φ = 25806334120.

The previous prime is 25806781073. The next prime is 25806781139. The reversal of 25806781123 is 32118760852.

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

It is a cyclic number.

It is not a de Polignac number, because 25806781123 - 2²⁵ = 25773226691 is a prime.

It is a super-2 number, since 2×25806781123² (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 25806781123.

It is not an unprimeable number, because it can be changed into a prime (25806781153) 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, 121336 + ... + 257557.

It is an arithmetic number, because the mean of its divisors is an integer number (6451807032).

Almost surely, 2^25806781123 is an apocalyptic number.

25806781123 is a deficient number, since it is larger than the sum of its proper divisors (447005).

25806781123 is an equidigital number, since it uses as much as digits as its factorization.

25806781123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447004.

The product of its (nonzero) digits is 161280, while the sum is 43.

The spelling of 25806781123 in words is "twenty-five billion, eight hundred six million, seven hundred eighty-one thousand, one hundred twenty-three".