18066453421 has 2 divisors, whose sum is σ = 18066453422. Its totient is φ = 18066453420.

The previous prime is 18066453407. The next prime is 18066453467. The reversal of 18066453421 is 12435466081.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15031986025 + 3034467396 = 122605^2 + 55086^2 .

It is an emirp because it is prime and its reverse (12435466081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18066453421 - 2²⁷ = 17932235693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18066453121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9033226710 + 9033226711.

It is an arithmetic number, because the mean of its divisors is an integer number (9033226711).

Almost surely, 2^18066453421 is an apocalyptic number.

It is an amenable number.

18066453421 is a deficient number, since it is larger than the sum of its proper divisors (1).

18066453421 is an equidigital number, since it uses as much as digits as its factorization.

18066453421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 138240, while the sum is 40.

The spelling of 18066453421 in words is "eighteen billion, sixty-six million, four hundred fifty-three thousand, four hundred twenty-one".