19928743 has 4 divisors (see below), whose sum is σ = 21101040. Its totient is φ = 18756448.

The previous prime is 19928719. The next prime is 19928773. The reversal of 19928743 is 34782991.

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 19928743 - 2⁹ = 19928231 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 19928743.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19928773) 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 3 ways as a sum of consecutive naturals, for example, 586123 + ... + 586156.

It is an arithmetic number, because the mean of its divisors is an integer number (5275260).

Almost surely, 2^19928743 is an apocalyptic number.

19928743 is a deficient number, since it is larger than the sum of its proper divisors (1172297).

19928743 is a wasteful number, since it uses less digits than its factorization.

19928743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1172296.

The product of its digits is 108864, while the sum is 43.

The square root of 19928743 is about 4464.1620714307. The cubic root of 19928743 is about 271.1190092892.

The spelling of 19928743 in words is "nineteen million, nine hundred twenty-eight thousand, seven hundred forty-three".