20728018 has 8 divisors (see below), whose sum is σ = 31150512. Its totient is φ = 10344516.

The previous prime is 20728009. The next prime is 20728033. The reversal of 20728018 is 81082702.

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

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 3 ways as a sum of consecutive naturals, for example, 8380 + ... + 10567.

It is an arithmetic number, because the mean of its divisors is an integer number (3893814).

Almost surely, 2^20728018 is an apocalyptic number.

20728018 is a deficient number, since it is larger than the sum of its proper divisors (10422494).

20728018 is a wasteful number, since it uses less digits than its factorization.

20728018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19496.

The product of its (nonzero) digits is 1792, while the sum is 28.

The square root of 20728018 is about 4552.8033122462. The cubic root of 20728018 is about 274.6961624962.

The spelling of 20728018 in words is "twenty million, seven hundred twenty-eight thousand, eighteen".