25811998 has 4 divisors (see below), whose sum is σ = 38718000. Its totient is φ = 12905998.

The previous prime is 25811993. The next prime is 25812011. The reversal of 25811998 is 89911852.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25811993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6452998 + ... + 6453001.

It is an arithmetic number, because the mean of its divisors is an integer number (9679500).

Almost surely, 2^25811998 is an apocalyptic number.

25811998 is a deficient number, since it is larger than the sum of its proper divisors (12906002).

25811998 is a wasteful number, since it uses less digits than its factorization.

25811998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12906001.

The product of its digits is 51840, while the sum is 43.

The square root of 25811998 is about 5080.5509543749. The cubic root of 25811998 is about 295.5338337334.

The spelling of 25811998 in words is "twenty-five million, eight hundred eleven thousand, nine hundred ninety-eight".