19821043 has 4 divisors (see below), whose sum is σ = 21622968. Its totient is φ = 18019120.

The previous prime is 19821041. The next prime is 19821049. The reversal of 19821043 is 34012891.

It is a happy number.

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 19821043 - 2¹ = 19821041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19821041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 900946 + ... + 900967.

It is an arithmetic number, because the mean of its divisors is an integer number (5405742).

Almost surely, 2^19821043 is an apocalyptic number.

19821043 is a deficient number, since it is larger than the sum of its proper divisors (1801925).

19821043 is a wasteful number, since it uses less digits than its factorization.

19821043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1801924.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 19821043 is about 4452.0829956325. The cubic root of 19821043 is about 270.6297281148.

It can be divided in two parts, 1982 and 1043, that added together give a square (3025 = 55²).

The spelling of 19821043 in words is "nineteen million, eight hundred twenty-one thousand, forty-three".