131289728 has 64 divisors (see below), whose sum is σ = 273839400. Its totient is φ = 62619648.

The previous prime is 131289713. The next prime is 131289733. The reversal of 131289728 is 827982131.

It can be written as a sum of positive squares in 4 ways, for example, as 31449664 + 99840064 = 5608^2 + 9992^2 .

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 419300 + ... + 419612.

Almost surely, 2^131289728 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 131289728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136919700).

131289728 is an abundant number, since it is smaller than the sum of its proper divisors (142549672).

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

131289728 is a wasteful number, since it uses less digits than its factorization.

131289728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 469 (or 457 counting only the distinct ones).

The product of its digits is 48384, while the sum is 41.

The square root of 131289728 is about 11458.1729782719. The cubic root of 131289728 is about 508.2494486563.

The spelling of 131289728 in words is "one hundred thirty-one million, two hundred eighty-nine thousand, seven hundred twenty-eight".