20662021 has 16 divisors (see below), whose sum is σ = 22752576. Its totient is φ = 18683136.

The previous prime is 20662009. The next prime is 20662039. The reversal of 20662021 is 12026602.

It is not a de Polignac number, because 20662021 - 2⁵ = 20661989 is a prime.

It is a super-2 number, since 2×20662021² = 853838223608882, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20662021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20662051) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67150 + ... + 67456.

It is an arithmetic number, because the mean of its divisors is an integer number (1422036).

Almost surely, 2^20662021 is an apocalyptic number.

It is an amenable number.

20662021 is a deficient number, since it is larger than the sum of its proper divisors (2090555).

20662021 is a wasteful number, since it uses less digits than its factorization.

20662021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 468.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 20662021 is about 4545.5495817338. The cubic root of 20662021 is about 274.4043127965.

Adding to 20662021 its reverse (12026602), we get a palindrome (32688623).

The spelling of 20662021 in words is "twenty million, six hundred sixty-two thousand, twenty-one".