18723943 has 4 divisors (see below), whose sum is σ = 21398800. Its totient is φ = 16049088.

The previous prime is 18723941. The next prime is 18723959. The reversal of 18723943 is 34932781.

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 18723943 - 2¹ = 18723941 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 (18723941) 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, 1337418 + ... + 1337431.

It is an arithmetic number, because the mean of its divisors is an integer number (5349700).

Almost surely, 2^18723943 is an apocalyptic number.

18723943 is a deficient number, since it is larger than the sum of its proper divisors (2674857).

18723943 is an equidigital number, since it uses as much as digits as its factorization.

18723943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2674856.

The product of its digits is 36288, while the sum is 37.

The square root of 18723943 is about 4327.1171696639. The cubic root of 18723943 is about 265.5415199352.

The spelling of 18723943 in words is "eighteen million, seven hundred twenty-three thousand, nine hundred forty-three".