25899987 has 32 divisors (see below), whose sum is σ = 37558080. Its totient is φ = 15841280.

The previous prime is 25899971. The next prime is 25900013. The reversal of 25899987 is 78999852.

It is a cyclic number.

It is not a de Polignac number, because 25899987 - 2⁴ = 25899971 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25899917) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 188983 + ... + 189119.

It is an arithmetic number, because the mean of its divisors is an integer number (1173690).

Almost surely, 2^25899987 is an apocalyptic number.

25899987 is a deficient number, since it is larger than the sum of its proper divisors (11658093).

25899987 is a wasteful number, since it uses less digits than its factorization.

25899987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263.

The product of its digits is 3265920, while the sum is 57.

The square root of 25899987 is about 5089.2029827862. The cubic root of 25899987 is about 295.8692621751.

The spelling of 25899987 in words is "twenty-five million, eight hundred ninety-nine thousand, nine hundred eighty-seven".