18394447 has 2 divisors, whose sum is σ = 18394448. Its totient is φ = 18394446.

The previous prime is 18394429. The next prime is 18394463. The reversal of 18394447 is 74449381.

It is a strong prime.

It is an emirp because it is prime and its reverse (74449381) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18394447 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18394417) 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, 9197223 + 9197224.

It is an arithmetic number, because the mean of its divisors is an integer number (9197224).

Almost surely, 2^18394447 is an apocalyptic number.

18394447 is the 2293-rd centered heptagonal number.

18394447 is a deficient number, since it is larger than the sum of its proper divisors (1).

18394447 is an equidigital number, since it uses as much as digits as its factorization.

18394447 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 40.

The square root of 18394447 is about 4288.8747941622. The cubic root of 18394447 is about 263.9746637378.

The spelling of 18394447 in words is "eighteen million, three hundred ninety-four thousand, four hundred forty-seven".