19944187 has 2 divisors, whose sum is σ = 19944188. Its totient is φ = 19944186.

The previous prime is 19944149. The next prime is 19944193. The reversal of 19944187 is 78144991.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19944187 is a prime.

It is a super-3 number, since 3×19944187³ (a number of 23 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (19944107) 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, 9972093 + 9972094.

It is an arithmetic number, because the mean of its divisors is an integer number (9972094).

Almost surely, 2^19944187 is an apocalyptic number.

19944187 is a deficient number, since it is larger than the sum of its proper divisors (1).

19944187 is an equidigital number, since it uses as much as digits as its factorization.

19944187 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 43.

The square root of 19944187 is about 4465.8915123411. The cubic root of 19944187 is about 271.1890267646.

The spelling of 19944187 in words is "nineteen million, nine hundred forty-four thousand, one hundred eighty-seven".