18821743 has 4 divisors (see below), whose sum is σ = 19428928. Its totient is φ = 18214560.

The previous prime is 18821717. The next prime is 18821749. The reversal of 18821743 is 34712881.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34712881 = 7 ⋅4958983.

It is a cyclic number.

It is not a de Polignac number, because 18821743 - 2⁵ = 18821711 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18821699 and 18821708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18821749) 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, 303546 + ... + 303607.

It is an arithmetic number, because the mean of its divisors is an integer number (4857232).

Almost surely, 2^18821743 is an apocalyptic number.

18821743 is a deficient number, since it is larger than the sum of its proper divisors (607185).

18821743 is an equidigital number, since it uses as much as digits as its factorization.

18821743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 607184.

The product of its digits is 10752, while the sum is 34.

The square root of 18821743 is about 4338.4032777048. The cubic root of 18821743 is about 266.0030479987.

The spelling of 18821743 in words is "eighteen million, eight hundred twenty-one thousand, seven hundred forty-three".