20791218 has 32 divisors (see below), whose sum is σ = 49591296. Its totient is φ = 5681808.

The previous prime is 20791213. The next prime is 20791229. The reversal of 20791218 is 81219702.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (20791213) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9796 + ... + 11727.

It is an arithmetic number, because the mean of its divisors is an integer number (1549728).

Almost surely, 2^20791218 is an apocalyptic number.

20791218 is an abundant number, since it is smaller than the sum of its proper divisors (28800078).

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

20791218 is a wasteful number, since it uses less digits than its factorization.

20791218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21558.

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 20791218 is about 4559.7388083091. The cubic root of 20791218 is about 274.9750633036.

The spelling of 20791218 in words is "twenty million, seven hundred ninety-one thousand, two hundred eighteen".