1311231000 has 64 divisors (see below), whose sum is σ = 4091050080. Its totient is φ = 349660800.

The previous prime is 1311230959. The next prime is 1311231001. The reversal of 1311231000 is 1321131.

It is a super-2 number, since 2×1311231000² = 3438653470722000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311231001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 215539 + ... + 221538.

Almost surely, 2^1311231000 is an apocalyptic number.

1311231000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1311231000 is an abundant number, since it is smaller than the sum of its proper divisors (2779819080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1311231000 is a wasteful number, since it uses less digits than its factorization.

1311231000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437101 (or 437087 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 12.

The square root of 1311231000 is about 36210.9237661786. The cubic root of 1311231000 is about 1094.5268070742.

Adding to 1311231000 its reverse (1321131), we get a palindrome (1312552131).

The spelling of 1311231000 in words is "one billion, three hundred eleven million, two hundred thirty-one thousand".