18006939 has 24 divisors (see below), whose sum is σ = 27061632. Its totient is φ = 11525760.

The previous prime is 18006931. The next prime is 18006943. The reversal of 18006939 is 93960081.

It is not a de Polignac number, because 18006939 - 2³ = 18006931 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18006931) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 64869 + ... + 65145.

It is an arithmetic number, because the mean of its divisors is an integer number (1127568).

Almost surely, 2^18006939 is an apocalyptic number.

18006939 is a deficient number, since it is larger than the sum of its proper divisors (9054693).

18006939 is a wasteful number, since it uses less digits than its factorization.

18006939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 547 (or 544 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 18006939 is about 4243.4583773144. The cubic root of 18006939 is about 262.1078116213.

The spelling of 18006939 in words is "eighteen million, six thousand, nine hundred thirty-nine".