19368421 has 2 divisors, whose sum is σ = 19368422. Its totient is φ = 19368420.

The previous prime is 19368413. The next prime is 19368431. The reversal of 19368421 is 12486391.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18533025 + 835396 = 4305^2 + 914^2 .

It is an emirp because it is prime and its reverse (12486391) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19368421 - 2³ = 19368413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19368431) 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, 9684210 + 9684211.

It is an arithmetic number, because the mean of its divisors is an integer number (9684211).

Almost surely, 2^19368421 is an apocalyptic number.

It is an amenable number.

19368421 is a deficient number, since it is larger than the sum of its proper divisors (1).

19368421 is an equidigital number, since it uses as much as digits as its factorization.

19368421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 34.

The square root of 19368421 is about 4400.9568277819. The cubic root of 19368421 is about 268.5538640322.

The spelling of 19368421 in words is "nineteen million, three hundred sixty-eight thousand, four hundred twenty-one".