1311211666 has 8 divisors (see below), whose sum is σ = 2082512700. Its totient is φ = 617040768.

The previous prime is 1311211663. The next prime is 1311211667. The reversal of 1311211666 is 6661121131.

It can be written as a sum of positive squares in 2 ways, for example, as 1181365641 + 129846025 = 34371^2 + 11395^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (1311211663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19282491 + ... + 19282558.

Almost surely, 2^1311211666 is an apocalyptic number.

1311211666 is a deficient number, since it is larger than the sum of its proper divisors (771301034).

1311211666 is a wasteful number, since it uses less digits than its factorization.

1311211666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38565068.

The product of its digits is 1296, while the sum is 28.

The square root of 1311211666 is about 36210.6568015550. The cubic root of 1311211666 is about 1094.5214274767.

Adding to 1311211666 its reverse (6661121131), we get a palindrome (7972332797).

The spelling of 1311211666 in words is "one billion, three hundred eleven million, two hundred eleven thousand, six hundred sixty-six".