18278441 has 4 divisors (see below), whose sum is σ = 18667392. Its totient is φ = 17889492.

The previous prime is 18278431. The next prime is 18278461. The reversal of 18278441 is 14487281.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18278441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18278401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194405 + ... + 194498.

It is an arithmetic number, because the mean of its divisors is an integer number (4666848).

Almost surely, 2^18278441 is an apocalyptic number.

It is an amenable number.

18278441 is a deficient number, since it is larger than the sum of its proper divisors (388951).

18278441 is an equidigital number, since it uses as much as digits as its factorization.

18278441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 388950.

The product of its digits is 14336, while the sum is 35.

The square root of 18278441 is about 4275.3293440389. The cubic root of 18278441 is about 263.4185675415.

The spelling of 18278441 in words is "eighteen million, two hundred seventy-eight thousand, four hundred forty-one".