18638949 has 8 divisors (see below), whose sum is σ = 28402240. Its totient is φ = 10650816.

The previous prime is 18638923. The next prime is 18638957. The reversal of 18638949 is 94983681.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18638949 - 2⁷ = 18638821 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18638898 and 18638907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18638959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 443764 + ... + 443805.

It is an arithmetic number, because the mean of its divisors is an integer number (3550280).

Almost surely, 2^18638949 is an apocalyptic number.

It is an amenable number.

18638949 is a deficient number, since it is larger than the sum of its proper divisors (9763291).

18638949 is an equidigital number, since it uses as much as digits as its factorization.

18638949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 887579.

The product of its digits is 373248, while the sum is 48.

The square root of 18638949 is about 4317.2849106817. The cubic root of 18638949 is about 265.1391176509.

The spelling of 18638949 in words is "eighteen million, six hundred thirty-eight thousand, nine hundred forty-nine".