6531128442 has 64 divisors (see below), whose sum is σ = 15516783360. Its totient is φ = 2029059072.

The previous prime is 6531128441. The next prime is 6531128447. The reversal of 6531128442 is 2448211356.

It is a happy number.

6531128442 is a `hidden beast` number, since 6 + 531 + 1 + 2 + 84 + 42 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 6531128397 and 6531128406.

It is not an unprimeable number, because it can be changed into a prime (6531128441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 60018 + ... + 129090.

It is an arithmetic number, because the mean of its divisors is an integer number (242449740).

Almost surely, 2^6531128442 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6531128442, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7758391680).

6531128442 is an abundant number, since it is smaller than the sum of its proper divisors (8985654918).

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

6531128442 is a wasteful number, since it uses less digits than its factorization.

6531128442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69204 (or 69198 counting only the distinct ones).

The product of its digits is 46080, while the sum is 36.

The square root of 6531128442 is about 80815.3973076913. The cubic root of 6531128442 is about 1869.2299957344.

Adding to 6531128442 its reverse (2448211356), we get a palindrome (8979339798).

The spelling of 6531128442 in words is "six billion, five hundred thirty-one million, one hundred twenty-eight thousand, four hundred forty-two".