20656128 has 78 divisors (see below), whose sum is σ = 56452372. Its totient is φ = 6717440.

The previous prime is 20656121. The next prime is 20656183. The reversal of 20656128 is 82165602.

It is a junction number, because it is equal to n+sod(n) for n = 20656095 and 20656104.

It is not an unprimeable number, because it can be changed into a prime (20656121) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 503788 + ... + 503828.

Almost surely, 2^20656128 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 20656128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28226186).

20656128 is an abundant number, since it is smaller than the sum of its proper divisors (35796244).

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

20656128 is an frugal number, since it uses more digits than its factorization.

20656128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109 (or 46 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 20656128 is about 4544.9013190607. The cubic root of 20656128 is about 274.3782227644.

The spelling of 20656128 in words is "twenty million, six hundred fifty-six thousand, one hundred twenty-eight".