19917223 has 2 divisors, whose sum is σ = 19917224. Its totient is φ = 19917222.

The previous prime is 19917203. The next prime is 19917281. The reversal of 19917223 is 32271991.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (32271991) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19917223 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19917203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9958611 + 9958612.

It is an arithmetic number, because the mean of its divisors is an integer number (9958612).

Almost surely, 2^19917223 is an apocalyptic number.

19917223 is a deficient number, since it is larger than the sum of its proper divisors (1).

19917223 is an equidigital number, since it uses as much as digits as its factorization.

19917223 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6804, while the sum is 34.

The square root of 19917223 is about 4462.8716091772. The cubic root of 19917223 is about 271.0667582433.

The spelling of 19917223 in words is "nineteen million, nine hundred seventeen thousand, two hundred twenty-three".