25689877987 has 4 divisors (see below), whose sum is σ = 26174592720. Its totient is φ = 25205163256.

The previous prime is 25689877963. The next prime is 25689878021. The reversal of 25689877987 is 78977898652.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 25689877987 - 2⁷ = 25689877859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25689877487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 242357287 + ... + 242357392.

It is an arithmetic number, because the mean of its divisors is an integer number (6543648180).

Almost surely, 2^25689877987 is an apocalyptic number.

25689877987 is a deficient number, since it is larger than the sum of its proper divisors (484714733).

25689877987 is an equidigital number, since it uses as much as digits as its factorization.

25689877987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 484714732.

The product of its digits is 853493760, while the sum is 76.

The spelling of 25689877987 in words is "twenty-five billion, six hundred eighty-nine million, eight hundred seventy-seven thousand, nine hundred eighty-seven".