131243440 has 80 divisors (see below), whose sum is σ = 317211840. Its totient is φ = 50457600.

The previous prime is 131243347. The next prime is 131243443. The reversal of 131243440 is 44342131.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (131243443) 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, 298741 + ... + 299179.

It is an arithmetic number, because the mean of its divisors is an integer number (3965148).

Almost surely, 2^131243440 is an apocalyptic number.

131243440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 131243440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (158605920).

131243440 is an abundant number, since it is smaller than the sum of its proper divisors (185968400).

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

131243440 is a wasteful number, since it uses less digits than its factorization.

131243440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 590 (or 584 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 131243440 is about 11456.1529319401. The cubic root of 131243440 is about 508.1897115234.

Adding to 131243440 its reverse (44342131), we get a palindrome (175585571).

The spelling of 131243440 in words is "one hundred thirty-one million, two hundred forty-three thousand, four hundred forty".