18238949 has 4 divisors (see below), whose sum is σ = 18276000. Its totient is φ = 18201900.

The previous prime is 18238937. The next prime is 18238981. The reversal of 18238949 is 94983281.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 18238949 - 2⁴ = 18238933 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 (18238919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17777 + ... + 18774.

It is an arithmetic number, because the mean of its divisors is an integer number (4569000).

Almost surely, 2^18238949 is an apocalyptic number.

It is an amenable number.

18238949 is a deficient number, since it is larger than the sum of its proper divisors (37051).

18238949 is an equidigital number, since it uses as much as digits as its factorization.

18238949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37050.

The product of its digits is 124416, while the sum is 44.

The square root of 18238949 is about 4270.7082550790. The cubic root of 18238949 is about 263.2287186153.

The spelling of 18238949 in words is "eighteen million, two hundred thirty-eight thousand, nine hundred forty-nine".