19993491 has 24 divisors (see below), whose sum is σ = 34744320. Its totient is φ = 10822896.

The previous prime is 19993489. The next prime is 19993517. The reversal of 19993491 is 19439991.

It is not a de Polignac number, because 19993491 - 2¹ = 19993489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19993451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7155 + ... + 9548.

It is an arithmetic number, because the mean of its divisors is an integer number (1447680).

Almost surely, 2^19993491 is an apocalyptic number.

19993491 is a deficient number, since it is larger than the sum of its proper divisors (14750829).

19993491 is a wasteful number, since it uses less digits than its factorization.

19993491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16735 (or 16732 counting only the distinct ones).

The product of its digits is 78732, while the sum is 45.

The square root of 19993491 is about 4471.4081674569. The cubic root of 19993491 is about 271.4123115573.

The spelling of 19993491 in words is "nineteen million, nine hundred ninety-three thousand, four hundred ninety-one".