20777256 has 64 divisors (see below), whose sum is σ = 59083200. Its totient is φ = 6761664.

The previous prime is 20777249. The next prime is 20777261. The reversal of 20777256 is 65277702.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 20777256.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8170 + ... + 10406.

It is an arithmetic number, because the mean of its divisors is an integer number (923175).

Almost surely, 2^20777256 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20777256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29541600).

20777256 is an abundant number, since it is smaller than the sum of its proper divisors (38305944).

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

20777256 is a wasteful number, since it uses less digits than its factorization.

20777256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2295 (or 2285 counting only the distinct ones).

The product of its (nonzero) digits is 41160, while the sum is 36.

The square root of 20777256 is about 4558.2075424447. The cubic root of 20777256 is about 274.9134978622.

The spelling of 20777256 in words is "twenty million, seven hundred seventy-seven thousand, two hundred fifty-six".