1311212018 has 4 divisors (see below), whose sum is σ = 1966818030. Its totient is φ = 655606008.

The previous prime is 1311212017. The next prime is 1311212041. The reversal of 1311212018 is 8102121131.

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., 1218917569 + 92294449 = 34913^2 + 9607^2 .

It is a super-2 number, since 2×1311212018² = 3438553912295264648, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1311212017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327803003 + ... + 327803006.

Almost surely, 2^1311212018 is an apocalyptic number.

1311212018 is a deficient number, since it is larger than the sum of its proper divisors (655606012).

1311212018 is an equidigital number, since it uses as much as digits as its factorization.

1311212018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 655606011.

The product of its (nonzero) digits is 96, while the sum is 20.

The square root of 1311212018 is about 36210.6616620023. The cubic root of 1311212018 is about 1094.5215254195.

Adding to 1311212018 its reverse (8102121131), we get a palindrome (9413333149).

The spelling of 1311212018 in words is "one billion, three hundred eleven million, two hundred twelve thousand, eighteen".