18728213 has 8 divisors (see below), whose sum is σ = 21451200. Its totient is φ = 16017120.

The previous prime is 18728197. The next prime is 18728249. The reversal of 18728213 is 31282781.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18728213 - 2⁴ = 18728197 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18728213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18728273) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 713 + ... + 6161.

It is an arithmetic number, because the mean of its divisors is an integer number (2681400).

Almost surely, 2^18728213 is an apocalyptic number.

It is an amenable number.

18728213 is a deficient number, since it is larger than the sum of its proper divisors (2722987).

18728213 is an equidigital number, since it uses as much as digits as its factorization.

18728213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5947.

The product of its digits is 5376, while the sum is 32.

The square root of 18728213 is about 4327.6105416269. The cubic root of 18728213 is about 265.5617040048.

The spelling of 18728213 in words is "eighteen million, seven hundred twenty-eight thousand, two hundred thirteen".