25431243991 has 2 divisors, whose sum is σ = 25431243992. Its totient is φ = 25431243990.

The previous prime is 25431243983. The next prime is 25431244009. The reversal of 25431243991 is 19934213452.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25431243991 - 2³ = 25431243983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25431243931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12715621995 + 12715621996.

It is an arithmetic number, because the mean of its divisors is an integer number (12715621996).

Almost surely, 2^25431243991 is an apocalyptic number.

25431243991 is a deficient number, since it is larger than the sum of its proper divisors (1).

25431243991 is an equidigital number, since it uses as much as digits as its factorization.

25431243991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 233280, while the sum is 43.

The spelling of 25431243991 in words is "twenty-five billion, four hundred thirty-one million, two hundred forty-three thousand, nine hundred ninety-one".