18309730 has 32 divisors (see below), whose sum is σ = 35899200. Its totient is φ = 6697152.

The previous prime is 18309721. The next prime is 18309737. The reversal of 18309730 is 3790381.

It is a junction number, because it is equal to n+sod(n) for n = 18309692 and 18309701.

It is not an unprimeable number, because it can be changed into a prime (18309737) 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 15 ways as a sum of consecutive naturals, for example, 3849 + ... + 7171.

It is an arithmetic number, because the mean of its divisors is an integer number (1121850).

Almost surely, 2^18309730 is an apocalyptic number.

18309730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18309730 is a deficient number, since it is larger than the sum of its proper divisors (17589470).

18309730 is a wasteful number, since it uses less digits than its factorization.

18309730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3378.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 18309730 is about 4278.9870296602. The cubic root of 18309730 is about 263.5687883232.

The spelling of 18309730 in words is "eighteen million, three hundred nine thousand, seven hundred thirty".