18172733 has 2 divisors, whose sum is σ = 18172734. Its totient is φ = 18172732.

The previous prime is 18172729. The next prime is 18172741. The reversal of 18172733 is 33727181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10004569 + 8168164 = 3163^2 + 2858^2 .

It is an emirp because it is prime and its reverse (33727181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18172733 - 2² = 18172729 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18172733.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18172723) 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, 9086366 + 9086367.

It is an arithmetic number, because the mean of its divisors is an integer number (9086367).

Almost surely, 2^18172733 is an apocalyptic number.

It is an amenable number.

18172733 is a deficient number, since it is larger than the sum of its proper divisors (1).

18172733 is an equidigital number, since it uses as much as digits as its factorization.

18172733 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7056, while the sum is 32.

The square root of 18172733 is about 4262.9488619968. The cubic root of 18172733 is about 262.9097841477.

The spelling of 18172733 in words is "eighteen million, one hundred seventy-two thousand, seven hundred thirty-three".