1311021231 has 8 divisors (see below), whose sum is σ = 1882492080. Its totient is φ = 806782272.

The previous prime is 1311021209. The next prime is 1311021233. The reversal of 1311021231 is 1321201131.

It is a happy number.

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

It is not a de Polignac number, because 1311021231 - 2⁶ = 1311021167 is a prime.

It is a super-2 number, since 2×1311021231² = 3437553336265510722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1311021231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311021233) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16807926 + ... + 16808003.

It is an arithmetic number, because the mean of its divisors is an integer number (235311510).

Almost surely, 2^1311021231 is an apocalyptic number.

1311021231 is a deficient number, since it is larger than the sum of its proper divisors (571470849).

1311021231 is a wasteful number, since it uses less digits than its factorization.

1311021231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33615945.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 1311021231 is about 36208.0271624953. The cubic root of 1311021231 is about 1094.4684369781.

Adding to 1311021231 its reverse (1321201131), we get a palindrome (2632222362).

The spelling of 1311021231 in words is "one billion, three hundred eleven million, twenty-one thousand, two hundred thirty-one".