20780800 has 108 divisors (see below), whose sum is σ = 54746496. Its totient is φ = 7782400.

The previous prime is 20780797. The next prime is 20780807. The reversal of 20780800 is 808702.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20780807) 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, 108705 + ... + 108895.

It is an arithmetic number, because the mean of its divisors is an integer number (506912).

Almost surely, 2^20780800 is an apocalyptic number.

20780800 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 20780800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27373248).

20780800 is an abundant number, since it is smaller than the sum of its proper divisors (33965696).

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

20780800 is a wasteful number, since it uses less digits than its factorization.

20780800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234 (or 215 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 20780800 is about 4558.5962751707. The cubic root of 20780800 is about 274.9291277421.

The spelling of 20780800 in words is "twenty million, seven hundred eighty thousand, eight hundred".