20820818 has 8 divisors (see below), whose sum is σ = 33068412. Its totient is φ = 9798016.

The previous prime is 20820817. The next prime is 20820829. The reversal of 20820818 is 81802802.

It can be written as a sum of positive squares in 2 ways, for example, as 17497489 + 3323329 = 4183^2 + 1823^2 .

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20820817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 306155 + ... + 306222.

Almost surely, 2^20820818 is an apocalyptic number.

20820818 is a deficient number, since it is larger than the sum of its proper divisors (12247594).

20820818 is a wasteful number, since it uses less digits than its factorization.

20820818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 612396.

The product of its (nonzero) digits is 2048, while the sum is 29.

The square root of 20820818 is about 4562.9834538381. The cubic root of 20820818 is about 275.1054934105.

The spelling of 20820818 in words is "twenty million, eight hundred twenty thousand, eight hundred eighteen".