20728178 has 16 divisors (see below), whose sum is σ = 31764480. Its totient is φ = 10142496.

The previous prime is 20728159. The next prime is 20728199. The reversal of 20728178 is 87182702.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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, 19550 + ... + 20582.

It is an arithmetic number, because the mean of its divisors is an integer number (1985280).

Almost surely, 2^20728178 is an apocalyptic number.

20728178 is a deficient number, since it is larger than the sum of its proper divisors (11036302).

20728178 is a wasteful number, since it uses less digits than its factorization.

20728178 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1241.

The product of its (nonzero) digits is 12544, while the sum is 35.

The square root of 20728178 is about 4552.8208838038. The cubic root of 20728178 is about 274.6968692895.

The spelling of 20728178 in words is "twenty million, seven hundred twenty-eight thousand, one hundred seventy-eight".