131128394 has 4 divisors (see below), whose sum is σ = 196692594. Its totient is φ = 65564196.

The previous prime is 131128379. The next prime is 131128397. The reversal of 131128394 is 493821131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 493821131 = 257 ⋅1921483.

It can be written as a sum of positive squares in only one way, i.e., 95785369 + 35343025 = 9787^2 + 5945^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 131128394.

It is not an unprimeable number, because it can be changed into a prime (131128397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32782097 + ... + 32782100.

Almost surely, 2^131128394 is an apocalyptic number.

131128394 is a deficient number, since it is larger than the sum of its proper divisors (65564200).

131128394 is an equidigital number, since it uses as much as digits as its factorization.

131128394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65564199.

The product of its digits is 5184, while the sum is 32.

The square root of 131128394 is about 11451.1306865305. The cubic root of 131128394 is about 508.0411776611.

The spelling of 131128394 in words is "one hundred thirty-one million, one hundred twenty-eight thousand, three hundred ninety-four".