18221743 has 2 divisors, whose sum is σ = 18221744. Its totient is φ = 18221742.

The previous prime is 18221729. The next prime is 18221761. The reversal of 18221743 is 34712281.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18221743 - 2⁵ = 18221711 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18221783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9110871 + 9110872.

It is an arithmetic number, because the mean of its divisors is an integer number (9110872).

Almost surely, 2^18221743 is an apocalyptic number.

18221743 is a deficient number, since it is larger than the sum of its proper divisors (1).

18221743 is an equidigital number, since it uses as much as digits as its factorization.

18221743 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2688, while the sum is 28.

The square root of 18221743 is about 4268.6933597999. The cubic root of 18221743 is about 263.1459189196.

The spelling of 18221743 in words is "eighteen million, two hundred twenty-one thousand, seven hundred forty-three".