18121886 has 4 divisors (see below), whose sum is σ = 27182832. Its totient is φ = 9060942.

The previous prime is 18121867. The next prime is 18121891. The reversal of 18121886 is 68812181.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4530470 + ... + 4530473.

It is an arithmetic number, because the mean of its divisors is an integer number (6795708).

Almost surely, 2^18121886 is an apocalyptic number.

18121886 is a deficient number, since it is larger than the sum of its proper divisors (9060946).

18121886 is an equidigital number, since it uses as much as digits as its factorization.

18121886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9060945.

The product of its digits is 6144, while the sum is 35.

The square root of 18121886 is about 4256.9808550192. The cubic root of 18121886 is about 262.6643493859.

The spelling of 18121886 in words is "eighteen million, one hundred twenty-one thousand, eight hundred eighty-six".