20643330 has 16 divisors (see below), whose sum is σ = 49544064. Its totient is φ = 5504880.

The previous prime is 20643323. The next prime is 20643347. The reversal of 20643330 is 3334602.

It is a super-2 number, since 2×20643330² = 852294146977800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20643297 and 20643306.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 344026 + ... + 344085.

It is an arithmetic number, because the mean of its divisors is an integer number (3096504).

Almost surely, 2^20643330 is an apocalyptic number.

20643330 is an abundant number, since it is smaller than the sum of its proper divisors (28900734).

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

20643330 is a wasteful number, since it uses less digits than its factorization.

20643330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 688121.

The product of its (nonzero) digits is 1296, while the sum is 21.

The square root of 20643330 is about 4543.4931495491. The cubic root of 20643330 is about 274.3215451858.

Adding to 20643330 its reverse (3334602), we get a palindrome (23977932).

The spelling of 20643330 in words is "twenty million, six hundred forty-three thousand, three hundred thirty".