25431215449 has 2 divisors, whose sum is σ = 25431215450. Its totient is φ = 25431215448.

The previous prime is 25431215429. The next prime is 25431215471. The reversal of 25431215449 is 94451213452.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25397203225 + 34012224 = 159365^2 + 5832^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25431215449 is a prime.

It is not a weakly prime, because it can be changed into another prime (25431215429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12715607724 + 12715607725.

It is an arithmetic number, because the mean of its divisors is an integer number (12715607725).

Almost surely, 2^25431215449 is an apocalyptic number.

It is an amenable number.

25431215449 is a deficient number, since it is larger than the sum of its proper divisors (1).

25431215449 is an equidigital number, since it uses as much as digits as its factorization.

25431215449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 172800, while the sum is 40.

The spelling of 25431215449 in words is "twenty-five billion, four hundred thirty-one million, two hundred fifteen thousand, four hundred forty-nine".