20550240 has 192 divisors, whose sum is σ = 74027520. Its totient is φ = 5322240.

The previous prime is 20550223. The next prime is 20550253. The reversal of 20550240 is 4205502.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 289405 + ... + 289475.

It is an arithmetic number, because the mean of its divisors is an integer number (385560).

Almost surely, 2^20550240 is an apocalyptic number.

20550240 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 20550240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37013760).

20550240 is an abundant number, since it is smaller than the sum of its proper divisors (53477280).

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

20550240 is a wasteful number, since it uses less digits than its factorization.

20550240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 18.

The square root of 20550240 is about 4533.2372538838. The cubic root of 20550240 is about 273.9085776655.

Adding to 20550240 its reverse (4205502), we get a palindrome (24755742).

The spelling of 20550240 in words is "twenty million, five hundred fifty thousand, two hundred forty".