18979243 has 4 divisors (see below), whose sum is σ = 19063080. Its totient is φ = 18895408.

The previous prime is 18979217. The next prime is 18979249. The reversal of 18979243 is 34297981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34297981 = 29 ⋅1182689.

It is a cyclic number.

It is not a de Polignac number, because 18979243 - 2²¹ = 16882091 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 18979243.

It is not an unprimeable number, because it can be changed into a prime (18979249) 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, 41578 + ... + 42031.

It is an arithmetic number, because the mean of its divisors is an integer number (4765770).

Almost surely, 2^18979243 is an apocalyptic number.

18979243 is a deficient number, since it is larger than the sum of its proper divisors (83837).

18979243 is an equidigital number, since it uses as much as digits as its factorization.

18979243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83836.

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

The square root of 18979243 is about 4356.5173016987. The cubic root of 18979243 is about 266.7429575121.

The spelling of 18979243 in words is "eighteen million, nine hundred seventy-nine thousand, two hundred forty-three".