19740239 has 2 divisors, whose sum is σ = 19740240. Its totient is φ = 19740238.

The previous prime is 19740209. The next prime is 19740241. The reversal of 19740239 is 93204791.

It is a strong prime.

It is an emirp because it is prime and its reverse (93204791) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19740239 - 2¹⁶ = 19674703 is a prime.

It is a Sophie Germain prime.

Together with 19740241, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 19740199 and 19740208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19740209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9870119 + 9870120.

It is an arithmetic number, because the mean of its divisors is an integer number (9870120).

Almost surely, 2^19740239 is an apocalyptic number.

19740239 is a deficient number, since it is larger than the sum of its proper divisors (1).

19740239 is an equidigital number, since it uses as much as digits as its factorization.

19740239 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 19740239 is about 4442.9988746341. The cubic root of 19740239 is about 270.2614705303.

The spelling of 19740239 in words is "nineteen million, seven hundred forty thousand, two hundred thirty-nine".