20784128 has 22 divisors (see below), whose sum is σ = 41550006. Its totient is φ = 10391552.

The previous prime is 20784077. The next prime is 20784143. The reversal of 20784128 is 82148702.

It can be written as a sum of positive squares in only one way, i.e., 17572864 + 3211264 = 4192^2 + 1792^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 20784094 and 20784103.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9125 + ... + 11172.

Almost surely, 2^20784128 is an apocalyptic number.

It is an amenable number.

20784128 is a deficient number, since it is larger than the sum of its proper divisors (20765878).

20784128 is an equidigital number, since it uses as much as digits as its factorization.

20784128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20317 (or 20299 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 20784128 is about 4558.9612852052. The cubic root of 20784128 is about 274.9438033930.

The spelling of 20784128 in words is "twenty million, seven hundred eighty-four thousand, one hundred twenty-eight".