18213773 has 2 divisors, whose sum is σ = 18213774. Its totient is φ = 18213772.

The previous prime is 18213763. The next prime is 18213781. The reversal of 18213773 is 37731281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14577124 + 3636649 = 3818^2 + 1907^2 .

It is a cyclic number.

It is not a de Polignac number, because 18213773 - 2¹⁰ = 18212749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18213703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9106886 + 9106887.

It is an arithmetic number, because the mean of its divisors is an integer number (9106887).

Almost surely, 2^18213773 is an apocalyptic number.

It is an amenable number.

18213773 is a deficient number, since it is larger than the sum of its proper divisors (1).

18213773 is an equidigital number, since it uses as much as digits as its factorization.

18213773 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7056, while the sum is 32.

The square root of 18213773 is about 4267.7597167601. The cubic root of 18213773 is about 263.1075475661.

The spelling of 18213773 in words is "eighteen million, two hundred thirteen thousand, seven hundred seventy-three".