18133498921 has 2 divisors, whose sum is σ = 18133498922. Its totient is φ = 18133498920.

The previous prime is 18133498909. The next prime is 18133498967. The reversal of 18133498921 is 12989433181.

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., 9892490521 + 8241008400 = 99461^2 + 90780^2 .

It is a cyclic number.

It is not a de Polignac number, because 18133498921 - 2²⁷ = 17999281193 is a prime.

It is not a weakly prime, because it can be changed into another prime (18133492921) 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, 9066749460 + 9066749461.

It is an arithmetic number, because the mean of its divisors is an integer number (9066749461).

Almost surely, 2^18133498921 is an apocalyptic number.

It is an amenable number.

18133498921 is a deficient number, since it is larger than the sum of its proper divisors (1).

18133498921 is an equidigital number, since it uses as much as digits as its factorization.

18133498921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 373248, while the sum is 49.

The spelling of 18133498921 in words is "eighteen billion, one hundred thirty-three million, four hundred ninety-eight thousand, nine hundred twenty-one".