25666987 has 2 divisors, whose sum is σ = 25666988. Its totient is φ = 25666986.

The previous prime is 25666981. The next prime is 25667023. The reversal of 25666987 is 78966652.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 25666987 - 2⁷ = 25666859 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25666987.

It is not a weakly prime, because it can be changed into another prime (25666981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12833493 + 12833494.

It is an arithmetic number, because the mean of its divisors is an integer number (12833494).

Almost surely, 2^25666987 is an apocalyptic number.

25666987 is a deficient number, since it is larger than the sum of its proper divisors (1).

25666987 is an equidigital number, since it uses as much as digits as its factorization.

25666987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1088640, while the sum is 49.

The square root of 25666987 is about 5066.2596656705. The cubic root of 25666987 is about 294.9793608083.

The spelling of 25666987 in words is "twenty-five million, six hundred sixty-six thousand, nine hundred eighty-seven".