20858218 has 32 divisors (see below), whose sum is σ = 34350480. Its totient is φ = 9461760.

The previous prime is 20858197. The next prime is 20858231. The reversal of 20858218 is 81285802.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 400689 + 20457529 = 633^2 + 4523^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

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 15 ways as a sum of consecutive naturals, for example, 184530 + ... + 184642.

Almost surely, 2^20858218 is an apocalyptic number.

20858218 is a deficient number, since it is larger than the sum of its proper divisors (13492262).

20858218 is a wasteful number, since it uses less digits than its factorization.

20858218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282.

The product of its (nonzero) digits is 10240, while the sum is 34.

The square root of 20858218 is about 4567.0798109952. The cubic root of 20858218 is about 275.2701169616.

The spelling of 20858218 in words is "twenty million, eight hundred fifty-eight thousand, two hundred eighteen".