18992209 has 2 divisors, whose sum is σ = 18992210. Its totient is φ = 18992208.

The previous prime is 18992161. The next prime is 18992219. The reversal of 18992209 is 90229981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9628609 + 9363600 = 3103^2 + 3060^2 .

It is a cyclic number.

It is not a de Polignac number, because 18992209 - 2¹⁷ = 18861137 is a prime.

It is not a weakly prime, because it can be changed into another prime (18992219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9496104 + 9496105.

It is an arithmetic number, because the mean of its divisors is an integer number (9496105).

Almost surely, 2^18992209 is an apocalyptic number.

It is an amenable number.

18992209 is a deficient number, since it is larger than the sum of its proper divisors (1).

18992209 is an equidigital number, since it uses as much as digits as its factorization.

18992209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 18992209 is about 4358.0051629157. The cubic root of 18992209 is about 266.8036870485.

The spelling of 18992209 in words is "eighteen million, nine hundred ninety-two thousand, two hundred nine".