20205550 has 24 divisors (see below), whose sum is σ = 39562200. Its totient is φ = 7656480.

The previous prime is 20205541. The next prime is 20205551. The reversal of 20205550 is 5550202.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20205551) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9685 + ... + 11584.

It is an arithmetic number, because the mean of its divisors is an integer number (1648425).

Almost surely, 2^20205550 is an apocalyptic number.

20205550 is a deficient number, since it is larger than the sum of its proper divisors (19356650).

20205550 is a wasteful number, since it uses less digits than its factorization.

20205550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21300 (or 21295 counting only the distinct ones).

The product of its (nonzero) digits is 500, while the sum is 19.

The square root of 20205550 is about 4495.0583978409. The cubic root of 20205550 is about 272.3685082294.

Adding to 20205550 its reverse (5550202), we get a palindrome (25755752).

The spelling of 20205550 in words is "twenty million, two hundred five thousand, five hundred fifty".