996543221 has 4 divisors (see below), whose sum is σ = 1010194572. Its totient is φ = 982891872.

The previous prime is 996543203. The next prime is 996543227. The reversal of 996543221 is 122345699.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 726302500 + 270240721 = 26950^2 + 16439^2 .

It is a cyclic number.

It is not a de Polignac number, because 996543221 - 2⁶ = 996543157 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (996543227) 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 3 ways as a sum of consecutive naturals, for example, 6825566 + ... + 6825711.

It is an arithmetic number, because the mean of its divisors is an integer number (252548643).

Almost surely, 2^996543221 is an apocalyptic number.

It is an amenable number.

996543221 is a deficient number, since it is larger than the sum of its proper divisors (13651351).

996543221 is a wasteful number, since it uses less digits than its factorization.

996543221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13651350.

The product of its digits is 116640, while the sum is 41.

The square root of 996543221 is about 31568.0728109905. The cubic root of 996543221 is about 998.8464100753.

The spelling of 996543221 in words is "nine hundred ninety-six million, five hundred forty-three thousand, two hundred twenty-one".