996191581 has 16 divisors (see below), whose sum is σ = 1242759168. Its totient is φ = 775782000.

The previous prime is 996191579. The next prime is 996191593. The reversal of 996191581 is 185191699.

It is not a de Polignac number, because 996191581 - 2¹ = 996191579 is a prime.

It is a super-2 number, since 2×996191581² = 1984795332110559122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (996191281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 178276 + ... + 183778.

It is an arithmetic number, because the mean of its divisors is an integer number (77672448).

Almost surely, 2^996191581 is an apocalyptic number.

It is an amenable number.

996191581 is a deficient number, since it is larger than the sum of its proper divisors (246567587).

996191581 is a wasteful number, since it uses less digits than its factorization.

996191581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7872.

The product of its digits is 174960, while the sum is 49.

The square root of 996191581 is about 31562.5027683167. The cubic root of 996191581 is about 998.7289120199.

The spelling of 996191581 in words is "nine hundred ninety-six million, one hundred ninety-one thousand, five hundred eighty-one".