18172019 has 2 divisors, whose sum is σ = 18172020. Its totient is φ = 18172018.

The previous prime is 18171991. The next prime is 18172073. The reversal of 18172019 is 91027181.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18172019 - 2⁸ = 18171763 is a prime.

It is a super-2 number, since 2×18172019² = 660444549072722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18171982 and 18172000.

It is not a weakly prime, because it can be changed into another prime (18172519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9086009 + 9086010.

It is an arithmetic number, because the mean of its divisors is an integer number (9086010).

Almost surely, 2^18172019 is an apocalyptic number.

18172019 is a deficient number, since it is larger than the sum of its proper divisors (1).

18172019 is an equidigital number, since it uses as much as digits as its factorization.

18172019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 29.

The square root of 18172019 is about 4262.8651163273. The cubic root of 18172019 is about 262.9063408930.

The spelling of 18172019 in words is "eighteen million, one hundred seventy-two thousand, nineteen".