19927109 has 2 divisors, whose sum is σ = 19927110. Its totient is φ = 19927108.

The previous prime is 19927091. The next prime is 19927121. The reversal of 19927109 is 90172991.

Together with previous prime (19927091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19802500 + 124609 = 4450^2 + 353^2 .

It is an emirp because it is prime and its reverse (90172991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19927109 - 2¹⁶ = 19861573 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19927129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9963554 + 9963555.

It is an arithmetic number, because the mean of its divisors is an integer number (9963555).

Almost surely, 2^19927109 is an apocalyptic number.

It is an amenable number.

19927109 is a deficient number, since it is larger than the sum of its proper divisors (1).

19927109 is an equidigital number, since it uses as much as digits as its factorization.

19927109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10206, while the sum is 38.

The square root of 19927109 is about 4463.9790546104. The cubic root of 19927109 is about 271.1115992120. Note that the first 3 decimals are identical.

The spelling of 19927109 in words is "nineteen million, nine hundred twenty-seven thousand, one hundred nine".