20660506 has 4 divisors (see below), whose sum is σ = 30990762. Its totient is φ = 10330252.

The previous prime is 20660501. The next prime is 20660527. The reversal of 20660506 is 60506602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20657025 + 3481 = 4545^2 + 59^2 .

It is not an unprimeable number, because it can be changed into a prime (20660501) by changing a digit.

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 as a sum of consecutive naturals, namely, 5165125 + ... + 5165128.

Almost surely, 2^20660506 is an apocalyptic number.

20660506 is a deficient number, since it is larger than the sum of its proper divisors (10330256).

20660506 is a wasteful number, since it uses less digits than its factorization.

20660506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10330255.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 20660506 is about 4545.3829321631. The cubic root of 20660506 is about 274.3976059228.

The spelling of 20660506 in words is "twenty million, six hundred sixty thousand, five hundred six".