18241813 has 2 divisors, whose sum is σ = 18241814. Its totient is φ = 18241812.

The previous prime is 18241807. The next prime is 18241831. The reversal of 18241813 is 31814281.

Together with next prime (18241831) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18173169 + 68644 = 4263^2 + 262^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18241813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18241513) 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, 9120906 + 9120907.

It is an arithmetic number, because the mean of its divisors is an integer number (9120907).

Almost surely, 2^18241813 is an apocalyptic number.

It is an amenable number.

18241813 is a deficient number, since it is larger than the sum of its proper divisors (1).

18241813 is an equidigital number, since it uses as much as digits as its factorization.

18241813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1536, while the sum is 28.

The square root of 18241813 is about 4271.0435492980. The cubic root of 18241813 is about 263.2424958637.

The spelling of 18241813 in words is "eighteen million, two hundred forty-one thousand, eight hundred thirteen".