19311389 has 2 divisors, whose sum is σ = 19311390. Its totient is φ = 19311388.

The previous prime is 19311317. The next prime is 19311403. The reversal of 19311389 is 98311391.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18992164 + 319225 = 4358^2 + 565^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19311389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19311289) 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, 9655694 + 9655695.

It is an arithmetic number, because the mean of its divisors is an integer number (9655695).

Almost surely, 2^19311389 is an apocalyptic number.

It is an amenable number.

19311389 is a deficient number, since it is larger than the sum of its proper divisors (1).

19311389 is an equidigital number, since it uses as much as digits as its factorization.

19311389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5832, while the sum is 35.

The square root of 19311389 is about 4394.4725508302. The cubic root of 19311389 is about 268.2900114811.

The spelling of 19311389 in words is "nineteen million, three hundred eleven thousand, three hundred eighty-nine".