1231011440 has 20 divisors (see below), whose sum is σ = 2862101784. Its totient is φ = 492404544.

The previous prime is 1231011437. The next prime is 1231011449. The reversal of 1231011440 is 441101321.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231011449) 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, 7693742 + ... + 7693901.

Almost surely, 2^1231011440 is an apocalyptic number.

1231011440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231011440 is an abundant number, since it is smaller than the sum of its proper divisors (1631090344).

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

1231011440 is a wasteful number, since it uses less digits than its factorization.

1231011440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15387656 (or 15387650 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 1231011440 is about 35085.7726151214. The cubic root of 1231011440 is about 1071.7348744735.

Adding to 1231011440 its reverse (441101321), we get a palindrome (1672112761).

The spelling of 1231011440 in words is "one billion, two hundred thirty-one million, eleven thousand, four hundred forty".