20518212 has 72 divisors (see below), whose sum is σ = 56723968. Its totient is φ = 5734080.

The previous prime is 20518193. The next prime is 20518217. The reversal of 20518212 is 21281502.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (20518217) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18333 + ... + 19419.

Almost surely, 2^20518212 is an apocalyptic number.

20518212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20518212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28361984).

20518212 is an abundant number, since it is smaller than the sum of its proper divisors (36205756).

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

20518212 is a wasteful number, since it uses less digits than its factorization.

20518212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1129 (or 1116 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 20518212 is about 4529.7033015419. The cubic root of 20518212 is about 273.7662061672.

Adding to 20518212 its reverse (21281502), we get a palindrome (41799714).

The spelling of 20518212 in words is "twenty million, five hundred eighteen thousand, two hundred twelve".