18728730 has 48 divisors (see below), whose sum is σ = 51563304. Its totient is φ = 4700160.

The previous prime is 18728729. The next prime is 18728741. The reversal of 18728730 is 3782781.

It can be written as a sum of positive squares in 4 ways, for example, as 15280281 + 3448449 = 3909^2 + 1857^2 .

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 23 ways as a sum of consecutive naturals, for example, 4591 + ... + 7650.

Almost surely, 2^18728730 is an apocalyptic number.

18728730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18728730 is an abundant number, since it is smaller than the sum of its proper divisors (32834574).

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

18728730 is a wasteful number, since it uses less digits than its factorization.

18728730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12271 (or 12268 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 18728730 is about 4327.6702739465. The cubic root of 18728730 is about 265.5641476289.

The spelling of 18728730 in words is "eighteen million, seven hundred twenty-eight thousand, seven hundred thirty".