19723243 has 2 divisors, whose sum is σ = 19723244. Its totient is φ = 19723242.

The previous prime is 19723189. The next prime is 19723267. The reversal of 19723243 is 34232791.

It is a strong prime.

It is an emirp because it is prime and its reverse (34232791) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19723243 - 2¹⁷ = 19592171 is a prime.

It is not a weakly prime, because it can be changed into another prime (19723343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9861621 + 9861622.

It is an arithmetic number, because the mean of its divisors is an integer number (9861622).

Almost surely, 2^19723243 is an apocalyptic number.

19723243 is a deficient number, since it is larger than the sum of its proper divisors (1).

19723243 is an equidigital number, since it uses as much as digits as its factorization.

19723243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 31.

The square root of 19723243 is about 4441.0857906598. The cubic root of 19723243 is about 270.1838847954.

The spelling of 19723243 in words is "nineteen million, seven hundred twenty-three thousand, two hundred forty-three".