20782880 has 24 divisors (see below), whose sum is σ = 49099932. Its totient is φ = 8313088.

The previous prime is 20782877. The next prime is 20782919. The reversal of 20782880 is 8828702.

It can be written as a sum of positive squares in 2 ways, for example, as 18627856 + 2155024 = 4316^2 + 1468^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20782880.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64787 + ... + 65106.

Almost surely, 2^20782880 is an apocalyptic number.

20782880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20782880 is an abundant number, since it is smaller than the sum of its proper divisors (28317052).

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

20782880 is a wasteful number, since it uses less digits than its factorization.

20782880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129908 (or 129900 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 35.

The square root of 20782880 is about 4558.8244098671. The cubic root of 20782880 is about 274.9383002075.

The spelling of 20782880 in words is "twenty million, seven hundred eighty-two thousand, eight hundred eighty".