25403843681 has 2 divisors, whose sum is σ = 25403843682. Its totient is φ = 25403843680.

The previous prime is 25403843659. The next prime is 25403843693. The reversal of 25403843681 is 18634830452.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24528571456 + 875272225 = 156616^2 + 29585^2 .

It is a cyclic number.

It is not a de Polignac number, because 25403843681 - 2³⁰ = 24330101857 is a prime.

It is a super-2 number, since 2×25403843681² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25403843611) 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, 12701921840 + 12701921841.

It is an arithmetic number, because the mean of its divisors is an integer number (12701921841).

Almost surely, 2^25403843681 is an apocalyptic number.

It is an amenable number.

25403843681 is a deficient number, since it is larger than the sum of its proper divisors (1).

25403843681 is an equidigital number, since it uses as much as digits as its factorization.

25403843681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 552960, while the sum is 44.

The spelling of 25403843681 in words is "twenty-five billion, four hundred three million, eight hundred forty-three thousand, six hundred eighty-one".