18272491 has 2 divisors, whose sum is σ = 18272492. Its totient is φ = 18272490.

The previous prime is 18272473. The next prime is 18272503. The reversal of 18272491 is 19427281.

It is a strong prime.

It is an emirp because it is prime and its reverse (19427281) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18272491 - 2⁵ = 18272459 is a prime.

It is not a weakly prime, because it can be changed into another prime (18272431) 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, 9136245 + 9136246.

It is an arithmetic number, because the mean of its divisors is an integer number (9136246).

Almost surely, 2^18272491 is an apocalyptic number.

18272491 is a deficient number, since it is larger than the sum of its proper divisors (1).

18272491 is an equidigital number, since it uses as much as digits as its factorization.

18272491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 34.

The square root of 18272491 is about 4274.6334345766. The cubic root of 18272491 is about 263.3899817597.

The spelling of 18272491 in words is "eighteen million, two hundred seventy-two thousand, four hundred ninety-one".