19439923 has 4 divisors (see below), whose sum is σ = 19806768. Its totient is φ = 19073080.

The previous prime is 19439921. The next prime is 19439933. The reversal of 19439923 is 32993491.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19439923 - 2¹ = 19439921 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19439921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 183343 + ... + 183448.

It is an arithmetic number, because the mean of its divisors is an integer number (4951692).

Almost surely, 2^19439923 is an apocalyptic number.

19439923 is a deficient number, since it is larger than the sum of its proper divisors (366845).

19439923 is an equidigital number, since it uses as much as digits as its factorization.

19439923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366844.

The product of its digits is 52488, while the sum is 40.

The square root of 19439923 is about 4409.0728050238. The cubic root of 19439923 is about 268.8839297846.

The spelling of 19439923 in words is "nineteen million, four hundred thirty-nine thousand, nine hundred twenty-three".