131640128 has 42 divisors (see below), whose sum is σ = 267510006. Its totient is φ = 64250368.

The previous prime is 131640127. The next prime is 131640137. The reversal of 131640128 is 821046131.

It can be written as a sum of positive squares in 3 ways, for example, as 109662784 + 21977344 = 10472^2 + 4688^2 .

It is a junction number, because it is equal to n+sod(n) for n = 131640097 and 131640106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131640121) 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 5 ways as a sum of consecutive naturals, for example, 668126 + ... + 668322.

Almost surely, 2^131640128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 131640128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133755003).

131640128 is an abundant number, since it is smaller than the sum of its proper divisors (135869878).

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

131640128 is an frugal number, since it uses more digits than its factorization.

131640128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459 (or 252 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 131640128 is about 11473.4531855061. The cubic root of 131640128 is about 508.7012037385.

Adding to 131640128 its reverse (821046131), we get a palindrome (952686259).

The spelling of 131640128 in words is "one hundred thirty-one million, six hundred forty thousand, one hundred twenty-eight".