18161111 has 2 divisors, whose sum is σ = 18161112. Its totient is φ = 18161110.

The previous prime is 18161089. The next prime is 18161119. The reversal of 18161111 is 11116181.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18161111 - 2¹⁴ = 18144727 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18161119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9080555 + 9080556.

It is an arithmetic number, because the mean of its divisors is an integer number (9080556).

Almost surely, 2^18161111 is an apocalyptic number.

18161111 is a deficient number, since it is larger than the sum of its proper divisors (1).

18161111 is an equidigital number, since it uses as much as digits as its factorization.

18161111 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48, while the sum is 20.

The square root of 18161111 is about 4261.5855030728. The cubic root of 18161111 is about 262.8537260026.

Adding to 18161111 its reverse (11116181), we get a palindrome (29277292).

The spelling of 18161111 in words is "eighteen million, one hundred sixty-one thousand, one hundred eleven".