18809949 has 16 divisors (see below), whose sum is σ = 26038208. Its totient is φ = 12068352.

The previous prime is 18809941. The next prime is 18809969. The reversal of 18809949 is 94990881.

It is not a de Polignac number, because 18809949 - 2³ = 18809941 is a prime.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18809898 and 18809907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18809941) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9894 + ... + 11640.

It is an arithmetic number, because the mean of its divisors is an integer number (1627388).

Almost surely, 2^18809949 is an apocalyptic number.

It is an amenable number.

18809949 is a deficient number, since it is larger than the sum of its proper divisors (7228259).

18809949 is a wasteful number, since it uses less digits than its factorization.

18809949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1884.

The product of its (nonzero) digits is 186624, while the sum is 48.

The square root of 18809949 is about 4337.0438088634. The cubic root of 18809949 is about 265.9474758260.

The spelling of 18809949 in words is "eighteen million, eight hundred nine thousand, nine hundred forty-nine".