20777280 has 112 divisors (see below), whose sum is σ = 68909184. Its totient is φ = 5294080.

The previous prime is 20777269. The next prime is 20777287. The reversal of 20777280 is 8277702.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20777287) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21610 + ... + 22550.

Almost surely, 2^20777280 is an apocalyptic number.

20777280 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 20777280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34454592).

20777280 is an abundant number, since it is smaller than the sum of its proper divisors (48131904).

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

20777280 is a wasteful number, since it uses less digits than its factorization.

20777280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 984 (or 974 counting only the distinct ones).

The product of its (nonzero) digits is 10976, while the sum is 33.

The square root of 20777280 is about 4558.2101750577. The cubic root of 20777280 is about 274.9136037139.

The spelling of 20777280 in words is "twenty million, seven hundred seventy-seven thousand, two hundred eighty".