20218650 has 48 divisors (see below), whose sum is σ = 51511584. Its totient is φ = 5244480.

The previous prime is 20218637. The next prime is 20218669. The reversal of 20218650 is 5681202.

It is a self number, because there is not a number n which added to its sum of digits gives 20218650.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3729 + ... + 7371.

It is an arithmetic number, because the mean of its divisors is an integer number (1073158).

Almost surely, 2^20218650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20218650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25755792).

20218650 is an abundant number, since it is smaller than the sum of its proper divisors (31292934).

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

20218650 is a wasteful number, since it uses less digits than its factorization.

20218650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3695 (or 3690 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 20218650 is about 4496.5153174431. The cubic root of 20218650 is about 272.4273576815.

Adding to 20218650 its reverse (5681202), we get a palindrome (25899852).

The spelling of 20218650 in words is "twenty million, two hundred eighteen thousand, six hundred fifty".