25602876661 has 2 divisors, whose sum is σ = 25602876662. Its totient is φ = 25602876660.

The previous prime is 25602876659. The next prime is 25602876667. The reversal of 25602876661 is 16667820652.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13620290436 + 11982586225 = 116706^2 + 109465^2 .

It is a cyclic number.

It is not a de Polignac number, because 25602876661 - 2¹ = 25602876659 is a prime.

Together with 25602876659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25602876667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12801438330 + 12801438331.

It is an arithmetic number, because the mean of its divisors is an integer number (12801438331).

Almost surely, 2^25602876661 is an apocalyptic number.

It is an amenable number.

25602876661 is a deficient number, since it is larger than the sum of its proper divisors (1).

25602876661 is an equidigital number, since it uses as much as digits as its factorization.

25602876661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1451520, while the sum is 49.

The spelling of 25602876661 in words is "twenty-five billion, six hundred two million, eight hundred seventy-six thousand, six hundred sixty-one".