18309942 has 64 divisors (see below), whose sum is σ = 47347200. Its totient is φ = 5136480.

The previous prime is 18309923. The next prime is 18309979. The reversal of 18309942 is 24990381.

It is a junction number, because it is equal to n+sod(n) for n = 18309897 and 18309906.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 21892 + ... + 22712.

It is an arithmetic number, because the mean of its divisors is an integer number (739800).

Almost surely, 2^18309942 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18309942, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23673600).

18309942 is an abundant number, since it is smaller than the sum of its proper divisors (29037258).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18309942 is a wasteful number, since it uses less digits than its factorization.

18309942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 898 (or 892 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 18309942 is about 4279.0118018066. The cubic root of 18309942 is about 263.5698055668.

The spelling of 18309942 in words is "eighteen million, three hundred nine thousand, nine hundred forty-two".