20207666 has 4 divisors (see below), whose sum is σ = 30311502. Its totient is φ = 10103832.

The previous prime is 20207651. The next prime is 20207683. The reversal of 20207666 is 66670202.

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., 19936225 + 271441 = 4465^2 + 521^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5051915 + ... + 5051918.

Almost surely, 2^20207666 is an apocalyptic number.

20207666 is a deficient number, since it is larger than the sum of its proper divisors (10103836).

20207666 is a wasteful number, since it uses less digits than its factorization.

20207666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10103835.

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 20207666 is about 4495.2937612574. The cubic root of 20207666 is about 272.3780157104.

Adding to 20207666 its reverse (66670202), we get a palindrome (86877868).

The spelling of 20207666 in words is "twenty million, two hundred seven thousand, six hundred sixty-six".