18450012221 has 2 divisors, whose sum is σ = 18450012222. Its totient is φ = 18450012220.

The previous prime is 18450012211. The next prime is 18450012253. The reversal of 18450012221 is 12221005481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11435949721 + 7014062500 = 106939^2 + 83750^2 .

It is a cyclic number.

It is not a de Polignac number, because 18450012221 - 2³⁰ = 17376270397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18450012211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9225006110 + 9225006111.

It is an arithmetic number, because the mean of its divisors is an integer number (9225006111).

Almost surely, 2^18450012221 is an apocalyptic number.

It is an amenable number.

18450012221 is a deficient number, since it is larger than the sum of its proper divisors (1).

18450012221 is an equidigital number, since it uses as much as digits as its factorization.

18450012221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1280, while the sum is 26.

The spelling of 18450012221 in words is "eighteen billion, four hundred fifty million, twelve thousand, two hundred twenty-one".