20003666 has 4 divisors (see below), whose sum is σ = 30005502. Its totient is φ = 10001832.

The previous prime is 20003663. The next prime is 20003671. The reversal of 20003666 is 66630002.

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., 19140625 + 863041 = 4375^2 + 929^2 .

It is not an unprimeable number, because it can be changed into a prime (20003663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5000915 + ... + 5000918.

Almost surely, 2^20003666 is an apocalyptic number.

20003666 is a deficient number, since it is larger than the sum of its proper divisors (10001836).

20003666 is a wasteful number, since it uses less digits than its factorization.

20003666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10001835.

The product of its (nonzero) digits is 1296, while the sum is 23.

The square root of 20003666 is about 4472.5458074792. The cubic root of 20003666 is about 271.4583457379.

Adding to 20003666 its reverse (66630002), we get a palindrome (86633668).

The spelling of 20003666 in words is "twenty million, three thousand, six hundred sixty-six".