131731840 has 64 divisors (see below), whose sum is σ = 323490960. Its totient is φ = 51259392.

The previous prime is 131731813. The next prime is 131731889. The reversal of 131731840 is 48137131.

It is a tau number, because it is divible by the number of its divisors (64).

It is a junction number, because it is equal to n+sod(n) for n = 131731799 and 131731808.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20899 + ... + 26461.

Almost surely, 2^131731840 is an apocalyptic number.

131731840 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 131731840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (161745480).

131731840 is an abundant number, since it is smaller than the sum of its proper divisors (191759120).

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

131731840 is an equidigital number, since it uses as much as digits as its factorization.

131731840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5619 (or 5607 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 131731840 is about 11477.4491939629. The cubic root of 131731840 is about 508.8193115305.

Adding to 131731840 its reverse (48137131), we get a palindrome (179868971).

The spelling of 131731840 in words is "one hundred thirty-one million, seven hundred thirty-one thousand, eight hundred forty".