131531616 has 72 divisors (see below), whose sum is σ = 380225664. Its totient is φ = 43119360.

The previous prime is 131531611. The next prime is 131531629. The reversal of 131531616 is 616135131.

131531616 is a `hidden beast` number, since 1 + 3 + 15 + 31 + 616 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a self number, because there is not a number n which added to its sum of digits gives 131531616.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131531611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13825 + ... + 21311.

It is an arithmetic number, because the mean of its divisors is an integer number (5280912).

Almost surely, 2^131531616 is an apocalyptic number.

131531616 is a gapful number since it is divisible by the number (16) 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 131531616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (190112832).

131531616 is an abundant number, since it is smaller than the sum of its proper divisors (248694048).

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

131531616 is a wasteful number, since it uses less digits than its factorization.

131531616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7564 (or 7553 counting only the distinct ones).

The product of its digits is 1620, while the sum is 27.

The square root of 131531616 is about 11468.7233814405. The cubic root of 131531616 is about 508.5613898380.

Adding to 131531616 its reverse (616135131), we get a palindrome (747666747).

The spelling of 131531616 in words is "one hundred thirty-one million, five hundred thirty-one thousand, six hundred sixteen".