18742281 has 8 divisors (see below), whose sum is σ = 25571040. Its totient is φ = 12204192.

The previous prime is 18742277. The next prime is 18742307. The reversal of 18742281 is 18224781.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18742281 - 2² = 18742277 is a prime.

It is a super-2 number, since 2×18742281² = 702546194165922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18742201) 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 in 7 ways as a sum of consecutive naturals, for example, 72516 + ... + 72773.

It is an arithmetic number, because the mean of its divisors is an integer number (3196380).

Almost surely, 2^18742281 is an apocalyptic number.

It is an amenable number.

18742281 is a deficient number, since it is larger than the sum of its proper divisors (6828759).

18742281 is a wasteful number, since it uses less digits than its factorization.

18742281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145335.

The product of its digits is 7168, while the sum is 33.

The square root of 18742281 is about 4329.2356138238. The cubic root of 18742281 is about 265.6281810184.

The spelling of 18742281 in words is "eighteen million, seven hundred forty-two thousand, two hundred eighty-one".