25851317993 has 2 divisors, whose sum is σ = 25851317994. Its totient is φ = 25851317992.

The previous prime is 25851317951. The next prime is 25851318007. The reversal of 25851317993 is 39971315852.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22228722649 + 3622595344 = 149093^2 + 60188^2 .

It is a cyclic number.

It is not a de Polignac number, because 25851317993 - 2¹⁶ = 25851252457 is a prime.

It is not a weakly prime, because it can be changed into another prime (25851317923) 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, 12925658996 + 12925658997.

It is an arithmetic number, because the mean of its divisors is an integer number (12925658997).

Almost surely, 2^25851317993 is an apocalyptic number.

It is an amenable number.

25851317993 is a deficient number, since it is larger than the sum of its proper divisors (1).

25851317993 is an equidigital number, since it uses as much as digits as its factorization.

25851317993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2041200, while the sum is 53.

The spelling of 25851317993 in words is "twenty-five billion, eight hundred fifty-one million, three hundred seventeen thousand, nine hundred ninety-three".