19785799 has 12 divisors (see below), whose sum is σ = 21976920. Its totient is φ = 17798000.

The previous prime is 19785797. The next prime is 19785803. The reversal of 19785799 is 99758791.

It is not a de Polignac number, because 19785799 - 2¹ = 19785797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19785791) 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 11 ways as a sum of consecutive naturals, for example, 11412 + ... + 13030.

It is an arithmetic number, because the mean of its divisors is an integer number (1831410).

Almost surely, 2^19785799 is an apocalyptic number.

19785799 is a deficient number, since it is larger than the sum of its proper divisors (2191121).

19785799 is a wasteful number, since it uses less digits than its factorization.

19785799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1742 (or 1731 counting only the distinct ones).

The product of its digits is 1428840, while the sum is 55.

The square root of 19785799 is about 4448.1230873257. The cubic root of 19785799 is about 270.4692297835.

It can be divided in two parts, 1978 and 5799, that added together give a palindrome (7777).

The spelling of 19785799 in words is "nineteen million, seven hundred eighty-five thousand, seven hundred ninety-nine".