25431563855 has 4 divisors (see below), whose sum is σ = 30517876632. Its totient is φ = 20345251080.

The previous prime is 25431563819. The next prime is 25431563881. The reversal of 25431563855 is 55836513452.

It is a happy number.

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

It is not a de Polignac number, because 25431563855 - 2¹² = 25431559759 is a prime.

It is a super-2 number, since 2×25431563855² (a number of 22 digits) contains 22 as substring.

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, 2543156381 + ... + 2543156390.

It is an arithmetic number, because the mean of its divisors is an integer number (7629469158).

Almost surely, 2^25431563855 is an apocalyptic number.

25431563855 is a deficient number, since it is larger than the sum of its proper divisors (5086312777).

25431563855 is an equidigital number, since it uses as much as digits as its factorization.

25431563855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5086312776.

The product of its digits is 2160000, while the sum is 47.

The spelling of 25431563855 in words is "twenty-five billion, four hundred thirty-one million, five hundred sixty-three thousand, eight hundred fifty-five".