20646568 has 16 divisors (see below), whose sum is σ = 40989780. Its totient is φ = 9715968.

The previous prime is 20646541. The next prime is 20646581. The reversal of 20646568 is 86564602.

It can be written as a sum of positive squares in 2 ways, for example, as 19518724 + 1127844 = 4418^2 + 1062^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75771 + ... + 76042.

Almost surely, 2^20646568 is an apocalyptic number.

It is an amenable number.

20646568 is a deficient number, since it is larger than the sum of its proper divisors (20343212).

20646568 is a wasteful number, since it uses less digits than its factorization.

20646568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151836 (or 151832 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 37.

The square root of 20646568 is about 4543.8494693376. The cubic root of 20646568 is about 274.3358872957.

The spelling of 20646568 in words is "twenty million, six hundred forty-six thousand, five hundred sixty-eight".