18268181 has 2 divisors, whose sum is σ = 18268182. Its totient is φ = 18268180.

The previous prime is 18268171. The next prime is 18268189. The reversal of 18268181 is 18186281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16728100 + 1540081 = 4090^2 + 1241^2 .

It is an emirp because it is prime and its reverse (18186281) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18268181 - 2¹⁰ = 18267157 is a prime.

It is a super-2 number, since 2×18268181² = 667452874097522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18268189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9134090 + 9134091.

It is an arithmetic number, because the mean of its divisors is an integer number (9134091).

Almost surely, 2^18268181 is an apocalyptic number.

It is an amenable number.

18268181 is a deficient number, since it is larger than the sum of its proper divisors (1).

18268181 is an equidigital number, since it uses as much as digits as its factorization.

18268181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6144, while the sum is 35.

The square root of 18268181 is about 4274.1292680498. The cubic root of 18268181 is about 263.3692712084.

The spelling of 18268181 in words is "eighteen million, two hundred sixty-eight thousand, one hundred eighty-one".