18091973 has 2 divisors, whose sum is σ = 18091974. Its totient is φ = 18091972.

The previous prime is 18091967. The next prime is 18091979. The reversal of 18091973 is 37919081.

It is a balanced prime because it is at equal distance from previous prime (18091967) and next prime (18091979).

It can be written as a sum of positive squares in only one way, i.e., 9229444 + 8862529 = 3038^2 + 2977^2 .

It is a cyclic number.

It is not a de Polignac number, because 18091973 - 2¹² = 18087877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18091979) 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, 9045986 + 9045987.

It is an arithmetic number, because the mean of its divisors is an integer number (9045987).

Almost surely, 2^18091973 is an apocalyptic number.

It is an amenable number.

18091973 is a deficient number, since it is larger than the sum of its proper divisors (1).

18091973 is an equidigital number, since it uses as much as digits as its factorization.

18091973 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13608, while the sum is 38.

The square root of 18091973 is about 4253.4659984535. The cubic root of 18091973 is about 262.5197469650.

The spelling of 18091973 in words is "eighteen million, ninety-one thousand, nine hundred seventy-three".