20206656 has 42 divisors (see below), whose sum is σ = 57920382. Its totient is φ = 6735360.

The previous prime is 20206651. The next prime is 20206657. The reversal of 20206656 is 65660202.

20206656 is a `hidden beast` number, since 2 + 0 + 2 + 0 + 6 + 656 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19501056 + 705600 = 4416^2 + 840^2 .

It is not an unprimeable number, because it can be changed into a prime (20206651) 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, 16965 + ... + 18116.

Almost surely, 2^20206656 is an apocalyptic number.

It is an amenable number.

20206656 is an abundant number, since it is smaller than the sum of its proper divisors (37713726).

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

20206656 is a wasteful number, since it uses less digits than its factorization.

20206656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35099 (or 35086 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 20206656 is about 4495.1814201431. The cubic root of 20206656 is about 272.3734777233.

Adding to 20206656 its reverse (65660202), we get a palindrome (85866858).

The spelling of 20206656 in words is "twenty million, two hundred six thousand, six hundred fifty-six".