19913423 has 4 divisors (see below), whose sum is σ = 20779248. Its totient is φ = 19047600.

The previous prime is 19913419. The next prime is 19913447. The reversal of 19913423 is 32431991.

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 19913423 - 2² = 19913419 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19913423.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19913323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 432878 + ... + 432923.

It is an arithmetic number, because the mean of its divisors is an integer number (5194812).

Almost surely, 2^19913423 is an apocalyptic number.

19913423 is a deficient number, since it is larger than the sum of its proper divisors (865825).

19913423 is an equidigital number, since it uses as much as digits as its factorization.

19913423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 865824.

The product of its digits is 5832, while the sum is 32.

The square root of 19913423 is about 4462.4458540132. The cubic root of 19913423 is about 271.0495182362.

The spelling of 19913423 in words is "nineteen million, nine hundred thirteen thousand, four hundred twenty-three".