131128666 has 16 divisors (see below), whose sum is σ = 202386024. Its totient is φ = 63673344.

The previous prime is 131128663. The next prime is 131128687. The reversal of 131128666 is 666821131.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 107557641 + 23571025 = 10371^2 + 4855^2 .

It is not an unprimeable number, because it can be changed into a prime (131128663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48486 + ... + 51118.

Almost surely, 2^131128666 is an apocalyptic number.

131128666 is a deficient number, since it is larger than the sum of its proper divisors (71257358).

131128666 is a wasteful number, since it uses less digits than its factorization.

131128666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3345.

The product of its digits is 10368, while the sum is 34.

The square root of 131128666 is about 11451.1425630808. The cubic root of 131128666 is about 508.0415289380.

Adding to 131128666 its reverse (666821131), we get a palindrome (797949797).

The spelling of 131128666 in words is "one hundred thirty-one million, one hundred twenty-eight thousand, six hundred sixty-six".