19831121 has 2 divisors, whose sum is σ = 19831122. Its totient is φ = 19831120.

The previous prime is 19831109. The next prime is 19831153. The reversal of 19831121 is 12113891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18800896 + 1030225 = 4336^2 + 1015^2 .

It is an emirp because it is prime and its reverse (12113891) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19831121 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (19831181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9915560 + 9915561.

It is an arithmetic number, because the mean of its divisors is an integer number (9915561).

Almost surely, 2^19831121 is an apocalyptic number.

It is an amenable number.

19831121 is a deficient number, since it is larger than the sum of its proper divisors (1).

19831121 is an equidigital number, since it uses as much as digits as its factorization.

19831121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 26.

The square root of 19831121 is about 4453.2146815531. The cubic root of 19831121 is about 270.6755875293.

The spelling of 19831121 in words is "nineteen million, eight hundred thirty-one thousand, one hundred twenty-one".