25491321599 has 2 divisors, whose sum is σ = 25491321600. Its totient is φ = 25491321598.

The previous prime is 25491321587. The next prime is 25491321637. The reversal of 25491321599 is 99512319452.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25491321599 - 2²⁴ = 25474544383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25491321539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12745660799 + 12745660800.

It is an arithmetic number, because the mean of its divisors is an integer number (12745660800).

Almost surely, 2^25491321599 is an apocalyptic number.

25491321599 is a deficient number, since it is larger than the sum of its proper divisors (1).

25491321599 is an equidigital number, since it uses as much as digits as its factorization.

25491321599 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 874800, while the sum is 50.

The spelling of 25491321599 in words is "twenty-five billion, four hundred ninety-one million, three hundred twenty-one thousand, five hundred ninety-nine".