131981640 has 128 divisors (see below), whose sum is σ = 462274560. Its totient is φ = 29516544.

The previous prime is 131981621. The next prime is 131981651. The reversal of 131981640 is 46189131.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 37809 + ... + 41151.

It is an arithmetic number, because the mean of its divisors is an integer number (3611520).

Almost surely, 2^131981640 is an apocalyptic number.

131981640 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 131981640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (231137280).

131981640 is an abundant number, since it is smaller than the sum of its proper divisors (330292920).

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

131981640 is a wasteful number, since it uses less digits than its factorization.

131981640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3411 (or 3407 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 131981640 is about 11488.3262488493. The cubic root of 131981640 is about 509.1407291612.

The spelling of 131981640 in words is "one hundred thirty-one million, nine hundred eighty-one thousand, six hundred forty".