18728330 has 16 divisors (see below), whose sum is σ = 33808104. Its totient is φ = 7469760.

The previous prime is 18728323. The next prime is 18728363. The reversal of 18728330 is 3382781.

It can be written as a sum of positive squares in 4 ways, for example, as 17952169 + 776161 = 4237^2 + 881^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1220 + ... + 6240.

Almost surely, 2^18728330 is an apocalyptic number.

18728330 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18728330 is a deficient number, since it is larger than the sum of its proper divisors (15079774).

18728330 is a wasteful number, since it uses less digits than its factorization.

18728330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5401.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 18728330 is about 4327.6240594580. The cubic root of 18728330 is about 265.5622570146.

The spelling of 18728330 in words is "eighteen million, seven hundred twenty-eight thousand, three hundred thirty".