20643104 has 12 divisors (see below), whose sum is σ = 40641174. Its totient is φ = 10321536.

The previous prime is 20643061. The next prime is 20643107. The reversal of 20643104 is 40134602.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 19536400 + 1106704 = 4420^2 + 1052^2 .

It is a super-2 number, since 2×20643104² = 852275485509632, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20643107) by changing a digit.

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 as a sum of consecutive naturals, namely, 322517 + ... + 322580.

Almost surely, 2^20643104 is an apocalyptic number.

It is an amenable number.

20643104 is a deficient number, since it is larger than the sum of its proper divisors (19998070).

20643104 is an equidigital number, since it uses as much as digits as its factorization.

20643104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645107 (or 645099 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 20643104 is about 4543.4682787492. The cubic root of 20643104 is about 274.3205441054.

Adding to 20643104 its reverse (40134602), we get a palindrome (60777706).

The spelling of 20643104 in words is "twenty million, six hundred forty-three thousand, one hundred four".