20641066 has 4 divisors (see below), whose sum is σ = 30961602. Its totient is φ = 10320532.

The previous prime is 20641063. The next prime is 20641073. The reversal of 20641066 is 66014602.

It is a happy number.

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., 16524225 + 4116841 = 4065^2 + 2029^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20641066.

It is not an unprimeable number, because it can be changed into a prime (20641063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5160265 + ... + 5160268.

Almost surely, 2^20641066 is an apocalyptic number.

20641066 is a deficient number, since it is larger than the sum of its proper divisors (10320536).

20641066 is a wasteful number, since it uses less digits than its factorization.

20641066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10320535.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 20641066 is about 4543.2439952087. The cubic root of 20641066 is about 274.3115163341.

Adding to 20641066 its reverse (66014602), we get a palindrome (86655668).

The spelling of 20641066 in words is "twenty million, six hundred forty-one thousand, sixty-six".