18191933 has 2 divisors, whose sum is σ = 18191934. Its totient is φ = 18191932.

The previous prime is 18191923. The next prime is 18191939. The reversal of 18191933 is 33919181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11648569 + 6543364 = 3413^2 + 2558^2 .

It is a cyclic number.

It is not a de Polignac number, because 18191933 - 2⁴ = 18191917 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18191893 and 18191902.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18191939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9095966 + 9095967.

It is an arithmetic number, because the mean of its divisors is an integer number (9095967).

Almost surely, 2^18191933 is an apocalyptic number.

It is an amenable number.

18191933 is a deficient number, since it is larger than the sum of its proper divisors (1).

18191933 is an equidigital number, since it uses as much as digits as its factorization.

18191933 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5832, while the sum is 35.

The square root of 18191933 is about 4265.2002297665. The cubic root of 18191933 is about 263.0023420688.

The spelling of 18191933 in words is "eighteen million, one hundred ninety-one thousand, nine hundred thirty-three".