25505491393 has 2 divisors, whose sum is σ = 25505491394. Its totient is φ = 25505491392.

The previous prime is 25505491373. The next prime is 25505491399. The reversal of 25505491393 is 39319450552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24866766864 + 638724529 = 157692^2 + 25273^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25505491393 is a prime.

It is not a weakly prime, because it can be changed into another prime (25505491399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12752745696 + 12752745697.

It is an arithmetic number, because the mean of its divisors is an integer number (12752745697).

Almost surely, 2^25505491393 is an apocalyptic number.

It is an amenable number.

25505491393 is a deficient number, since it is larger than the sum of its proper divisors (1).

25505491393 is an equidigital number, since it uses as much as digits as its factorization.

25505491393 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 729000, while the sum is 46.

The spelling of 25505491393 in words is "twenty-five billion, five hundred five million, four hundred ninety-one thousand, three hundred ninety-three".