18172423 has 2 divisors, whose sum is σ = 18172424. Its totient is φ = 18172422.

The previous prime is 18172391. The next prime is 18172459. The reversal of 18172423 is 32427181.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18172423 - 2⁵ = 18172391 is a prime.

It is equal to p_1161586 and since 18172423 and 1161586 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 18172391 and 18172400.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18172463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9086211 + 9086212.

It is an arithmetic number, because the mean of its divisors is an integer number (9086212).

Almost surely, 2^18172423 is an apocalyptic number.

18172423 is a deficient number, since it is larger than the sum of its proper divisors (1).

18172423 is an equidigital number, since it uses as much as digits as its factorization.

18172423 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2688, while the sum is 28.

The square root of 18172423 is about 4262.9125020343. The cubic root of 18172423 is about 262.9082891883.

The spelling of 18172423 in words is "eighteen million, one hundred seventy-two thousand, four hundred twenty-three".