131128909 has 2 divisors, whose sum is σ = 131128910. Its totient is φ = 131128908.

The previous prime is 131128883. The next prime is 131128967. The reversal of 131128909 is 909821131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 128187684 + 2941225 = 11322^2 + 1715^2 .

It is an emirp because it is prime and its reverse (909821131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 131128909 - 2⁹ = 131128397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131128969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65564454 + 65564455.

It is an arithmetic number, because the mean of its divisors is an integer number (65564455).

Almost surely, 2^131128909 is an apocalyptic number.

It is an amenable number.

131128909 is a deficient number, since it is larger than the sum of its proper divisors (1).

131128909 is an equidigital number, since it uses as much as digits as its factorization.

131128909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 34.

The square root of 131128909 is about 11451.1531733708. The cubic root of 131128909 is about 508.0418427621.

The spelling of 131128909 in words is "one hundred thirty-one million, one hundred twenty-eight thousand, nine hundred nine".