18548889221 has 2 divisors, whose sum is σ = 18548889222. Its totient is φ = 18548889220.

The previous prime is 18548889217. The next prime is 18548889323. The reversal of 18548889221 is 12298884581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13251232996 + 5297656225 = 115114^2 + 72785^2 .

It is a cyclic number.

It is not a de Polignac number, because 18548889221 - 2² = 18548889217 is a prime.

It is a super-2 number, since 2×18548889221² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18548879221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9274444610 + 9274444611.

It is an arithmetic number, because the mean of its divisors is an integer number (9274444611).

Almost surely, 2^18548889221 is an apocalyptic number.

It is an amenable number.

18548889221 is a deficient number, since it is larger than the sum of its proper divisors (1).

18548889221 is an equidigital number, since it uses as much as digits as its factorization.

18548889221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2949120, while the sum is 56.

The spelling of 18548889221 in words is "eighteen billion, five hundred forty-eight million, eight hundred eighty-nine thousand, two hundred twenty-one".