20550780 has 96 divisors (see below), whose sum is σ = 67334400. Its totient is φ = 5189184.

The previous prime is 20550769. The next prime is 20550781. The reversal of 20550780 is 8705502.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20550781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9259 + ... + 11261.

It is an arithmetic number, because the mean of its divisors is an integer number (701400).

Almost surely, 2^20550780 is an apocalyptic number.

20550780 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 20550780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33667200).

20550780 is an abundant number, since it is smaller than the sum of its proper divisors (46783620).

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

20550780 is a wasteful number, since it uses less digits than its factorization.

20550780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2040 (or 2032 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 27.

The square root of 20550780 is about 4533.2968135784. The cubic root of 20550780 is about 273.9109768157.

The spelling of 20550780 in words is "twenty million, five hundred fifty thousand, seven hundred eighty".