19504993 has 4 divisors (see below), whose sum is σ = 19516420. Its totient is φ = 19493568.

The previous prime is 19504951. The next prime is 19504997. The reversal of 19504993 is 39940591.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 39940591 = 3257 ⋅12263.

It can be written as a sum of positive squares in 2 ways, for example, as 17909824 + 1595169 = 4232^2 + 1263^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19504993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19504997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2580 + ... + 6757.

It is an arithmetic number, because the mean of its divisors is an integer number (4879105).

Almost surely, 2^19504993 is an apocalyptic number.

It is an amenable number.

19504993 is a deficient number, since it is larger than the sum of its proper divisors (11427).

19504993 is an equidigital number, since it uses as much as digits as its factorization.

19504993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11426.

The product of its (nonzero) digits is 43740, while the sum is 40.

The square root of 19504993 is about 4416.4457429023. The cubic root of 19504993 is about 269.1836016187.

The spelling of 19504993 in words is "nineteen million, five hundred four thousand, nine hundred ninety-three".