18720930 has 16 divisors (see below), whose sum is σ = 44930304. Its totient is φ = 4992240.

The previous prime is 18720907. The next prime is 18720941. The reversal of 18720930 is 3902781.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 624031 = 18720930 / (1 + 8 + 7 + 2 + 0 + 9 + 3 + 0).

It is an unprimeable number.

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, 311986 + ... + 312045.

It is an arithmetic number, because the mean of its divisors is an integer number (2808144).

Almost surely, 2^18720930 is an apocalyptic number.

18720930 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18720930 is an abundant number, since it is smaller than the sum of its proper divisors (26209374).

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

18720930 is a wasteful number, since it uses less digits than its factorization.

18720930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 624041.

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 18720930 is about 4326.7690023850. The cubic root of 18720930 is about 265.5272757930.

The spelling of 18720930 in words is "eighteen million, seven hundred twenty thousand, nine hundred thirty".