25649684987 has 2 divisors, whose sum is σ = 25649684988. Its totient is φ = 25649684986.

The previous prime is 25649684981. The next prime is 25649685011. The reversal of 25649684987 is 78948694652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25649684987 - 2⁴ = 25649684971 is a prime.

It is not a weakly prime, because it can be changed into another prime (25649684981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12824842493 + 12824842494.

It is an arithmetic number, because the mean of its divisors is an integer number (12824842494).

Almost surely, 2^25649684987 is an apocalyptic number.

25649684987 is a deficient number, since it is larger than the sum of its proper divisors (1).

25649684987 is an equidigital number, since it uses as much as digits as its factorization.

25649684987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 209018880, while the sum is 68.

The spelling of 25649684987 in words is "twenty-five billion, six hundred forty-nine million, six hundred eighty-four thousand, nine hundred eighty-seven".