18281943 has 20 divisors (see below), whose sum is σ = 27665440. Its totient is φ = 12029472.

The previous prime is 18281929. The next prime is 18281969. The reversal of 18281943 is 34918281.

It is not a de Polignac number, because 18281943 - 2⁴ = 18281927 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18281898 and 18281907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18281903) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4971 + ... + 7827.

It is an arithmetic number, because the mean of its divisors is an integer number (1383272).

Almost surely, 2^18281943 is an apocalyptic number.

18281943 is a deficient number, since it is larger than the sum of its proper divisors (9383497).

18281943 is an equidigital number, since it uses as much as digits as its factorization.

18281943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2948 (or 2939 counting only the distinct ones).

The product of its digits is 13824, while the sum is 36.

The square root of 18281943 is about 4275.7388835148. The cubic root of 18281943 is about 263.4353894158.

It can be divided in two parts, 18 and 281943, that added together give a square (281961 = 531²).

The spelling of 18281943 in words is "eighteen million, two hundred eighty-one thousand, nine hundred forty-three".