18944281 has 4 divisors (see below), whose sum is σ = 18954000. Its totient is φ = 18934564.

The previous prime is 18944269. The next prime is 18944293. The reversal of 18944281 is 18244981.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 18244981 = 181 ⋅100801.

It is an interprime number because it is at equal distance from previous prime (18944269) and next prime (18944293).

It is a cyclic number.

It is not a de Polignac number, because 18944281 - 2¹⁷ = 18813209 is a prime.

It is a super-2 number, since 2×18944281² = 717771565213922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18944281.

It is not an unprimeable number, because it can be changed into a prime (18944201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 811 + ... + 6208.

It is an arithmetic number, because the mean of its divisors is an integer number (4738500).

Almost surely, 2^18944281 is an apocalyptic number.

It is an amenable number.

18944281 is a deficient number, since it is larger than the sum of its proper divisors (9719).

18944281 is an equidigital number, since it uses as much as digits as its factorization.

18944281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9718.

The product of its digits is 18432, while the sum is 37.

The square root of 18944281 is about 4352.5028431926. The cubic root of 18944281 is about 266.5790661915.

The spelling of 18944281 in words is "eighteen million, nine hundred forty-four thousand, two hundred eighty-one".