1231131144 has 64 divisors (see below), whose sum is σ = 3244363200. Its totient is φ = 388233216.

The previous prime is 1231131137. The next prime is 1231131157. The reversal of 1231131144 is 4411311321.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 1231131144.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 433152 + ... + 435984.

It is an arithmetic number, because the mean of its divisors is an integer number (50693175).

Almost surely, 2^1231131144 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1231131144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1622181600).

1231131144 is an abundant number, since it is smaller than the sum of its proper divisors (2013232056).

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

1231131144 is a wasteful number, since it uses less digits than its factorization.

1231131144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3814 (or 3810 counting only the distinct ones).

The product of its digits is 288, while the sum is 21.

The square root of 1231131144 is about 35087.4784502962. The cubic root of 1231131144 is about 1071.7696119772.

Adding to 1231131144 its reverse (4411311321), we get a palindrome (5642442465).

The spelling of 1231131144 in words is "one billion, two hundred thirty-one million, one hundred thirty-one thousand, one hundred forty-four".