20243666 has 4 divisors (see below), whose sum is σ = 30365502. Its totient is φ = 10121832.

The previous prime is 20243659. The next prime is 20243677. The reversal of 20243666 is 66634202.

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., 18241441 + 2002225 = 4271^2 + 1415^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5060915 + ... + 5060918.

Almost surely, 2^20243666 is an apocalyptic number.

20243666 is a deficient number, since it is larger than the sum of its proper divisors (10121836).

20243666 is a wasteful number, since it uses less digits than its factorization.

20243666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10121835.

The product of its (nonzero) digits is 10368, while the sum is 29.

The square root of 20243666 is about 4499.2961671799. The cubic root of 20243666 is about 272.5396670925.

Adding to 20243666 its reverse (66634202), we get a palindrome (86877868).

The spelling of 20243666 in words is "twenty million, two hundred forty-three thousand, six hundred sixty-six".