18949 has 4 divisors (see below), whose sum is σ = 21664. Its totient is φ = 16236.

The previous prime is 18947. The next prime is 18959. The reversal of 18949 is 94981.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 94981 = 19 ⋅4999.

It is a cyclic number.

It is not a de Polignac number, because 18949 - 2¹ = 18947 is a prime.

It is an alternating number because its digits alternate between odd and even.

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 18949.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1347 + ... + 1360.

It is an arithmetic number, because the mean of its divisors is an integer number (5416).

2¹⁸⁹⁴⁹ is an apocalyptic number.

It is an amenable number.

18949 is a deficient number, since it is larger than the sum of its proper divisors (2715).

18949 is an equidigital number, since it uses as much as digits as its factorization.

18949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2714.

The product of its digits is 2592, while the sum is 31.

The square root of 18949 is about 137.6553667679. The cubic root of 18949 is about 26.6601199207.

It can be divided in two parts, 189 and 49, that multiplied together give a cube (9261 = 21³).

The spelling of 18949 in words is "eighteen thousand, nine hundred forty-nine".