20550400 has 162 divisors, whose sum is σ = 57978060. Its totient is φ = 7188480.

The previous prime is 20550391. The next prime is 20550403. The reversal of 20550400 is 405502.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (20550403) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1081591 + ... + 1081609.

Almost surely, 2^20550400 is an apocalyptic number.

20550400 is a gapful number since it is divisible by the number (20) 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 20550400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28989030).

20550400 is an abundant number, since it is smaller than the sum of its proper divisors (37427660).

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

20550400 is a wasteful number, since it uses less digits than its factorization.

20550400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71 (or 39 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 16.

The square root of 20550400 is about 4533.2549012823. The cubic root of 20550400 is about 273.9092885292.

Adding to 20550400 its reverse (405502), we get a palindrome (20955902).

It can be divided in two parts, 205 and 50400, that added together give a palindrome (50605).

The spelling of 20550400 in words is "twenty million, five hundred fifty thousand, four hundred".