20538656 has 12 divisors (see below), whose sum is σ = 40435542. Its totient is φ = 10269312.

The previous prime is 20538643. The next prime is 20538673. The reversal of 20538656 is 65683502.

It can be written as a sum of positive squares in only one way, i.e., 20394256 + 144400 = 4516^2 + 380^2 .

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320885 + ... + 320948.

Almost surely, 2^20538656 is an apocalyptic number.

It is an amenable number.

20538656 is a deficient number, since it is larger than the sum of its proper divisors (19896886).

20538656 is an equidigital number, since it uses as much as digits as its factorization.

20538656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641843 (or 641835 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 20538656 is about 4531.9593996416. The cubic root of 20538656 is about 273.8571013269.

The spelling of 20538656 in words is "twenty million, five hundred thirty-eight thousand, six hundred fifty-six".