20218550 has 24 divisors (see below), whose sum is σ = 41026392. Its totient is φ = 7352000.

The previous prime is 20218547. The next prime is 20218567. The reversal of 20218550 is 5581202.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17831 + ... + 18930.

It is an arithmetic number, because the mean of its divisors is an integer number (1709433).

Almost surely, 2^20218550 is an apocalyptic number.

20218550 is an abundant number, since it is smaller than the sum of its proper divisors (20807842).

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

20218550 is a wasteful number, since it uses less digits than its factorization.

20218550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36784 (or 36779 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 23.

The square root of 20218550 is about 4496.5041977074. The cubic root of 20218550 is about 272.4269085453.

Adding to 20218550 its reverse (5581202), we get a palindrome (25799752).

The spelling of 20218550 in words is "twenty million, two hundred eighteen thousand, five hundred fifty".