19981229 has 2 divisors, whose sum is σ = 19981230. Its totient is φ = 19981228.

The previous prime is 19981223. The next prime is 19981231. The reversal of 19981229 is 92218991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11744329 + 8236900 = 3427^2 + 2870^2 .

It is a cyclic number.

It is not a de Polignac number, because 19981229 - 2⁸ = 19980973 is a prime.

It is a Sophie Germain prime.

Together with 19981231, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19981223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9990614 + 9990615.

It is an arithmetic number, because the mean of its divisors is an integer number (9990615).

Almost surely, 2^19981229 is an apocalyptic number.

It is an amenable number.

19981229 is a deficient number, since it is larger than the sum of its proper divisors (1).

19981229 is an equidigital number, since it uses as much as digits as its factorization.

19981229 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 41.

The square root of 19981229 is about 4470.0368007434. The cubic root of 19981229 is about 271.3568145231.

It can be divided in two parts, 1998 and 1229, that multiplied together give a palindrome (2455542).

The spelling of 19981229 in words is "nineteen million, nine hundred eighty-one thousand, two hundred twenty-nine".