25290427661 has 2 divisors, whose sum is σ = 25290427662. Its totient is φ = 25290427660.

The previous prime is 25290427651. The next prime is 25290427667. The reversal of 25290427661 is 16672409252.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19714968100 + 5575459561 = 140410^2 + 74669^2 .

It is a cyclic number.

It is not a de Polignac number, because 25290427661 - 2²⁶ = 25223318797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25290427667) 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, 12645213830 + 12645213831.

It is an arithmetic number, because the mean of its divisors is an integer number (12645213831).

Almost surely, 2^25290427661 is an apocalyptic number.

It is an amenable number.

25290427661 is a deficient number, since it is larger than the sum of its proper divisors (1).

25290427661 is an equidigital number, since it uses as much as digits as its factorization.

25290427661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 362880, while the sum is 44.

The spelling of 25290427661 in words is "twenty-five billion, two hundred ninety million, four hundred twenty-seven thousand, six hundred sixty-one".