18481739 has 4 divisors (see below), whose sum is σ = 18524856. Its totient is φ = 18438624.

The previous prime is 18481721. The next prime is 18481741. The reversal of 18481739 is 93718481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93718481 = 157 ⋅596933.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18481739 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18481696 and 18481705.

It is not an unprimeable number, because it can be changed into a prime (18481709) 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, 20909 + ... + 21774.

It is an arithmetic number, because the mean of its divisors is an integer number (4631214).

Almost surely, 2^18481739 is an apocalyptic number.

18481739 is a deficient number, since it is larger than the sum of its proper divisors (43117).

18481739 is an equidigital number, since it uses as much as digits as its factorization.

18481739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43116.

The product of its digits is 48384, while the sum is 41.

The square root of 18481739 is about 4299.0393112880. The cubic root of 18481739 is about 264.3915743716.

The spelling of 18481739 in words is "eighteen million, four hundred eighty-one thousand, seven hundred thirty-nine".