19312421 has 2 divisors, whose sum is σ = 19312422. Its totient is φ = 19312420.

The previous prime is 19312399. The next prime is 19312439. The reversal of 19312421 is 12421391.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18232900 + 1079521 = 4270^2 + 1039^2 .

It is an emirp because it is prime and its reverse (12421391) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19312421 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19312471) 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, 9656210 + 9656211.

It is an arithmetic number, because the mean of its divisors is an integer number (9656211).

Almost surely, 2^19312421 is an apocalyptic number.

It is an amenable number.

19312421 is a deficient number, since it is larger than the sum of its proper divisors (1).

19312421 is an equidigital number, since it uses as much as digits as its factorization.

19312421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432, while the sum is 23.

The square root of 19312421 is about 4394.5899694966. The cubic root of 19312421 is about 268.2947905325.

The spelling of 19312421 in words is "nineteen million, three hundred twelve thousand, four hundred twenty-one".