996901991 has 4 divisors (see below), whose sum is σ = 1002871632. Its totient is φ = 990932352.

The previous prime is 996901973. The next prime is 996901993. The reversal of 996901991 is 199109699.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-996901991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (996901993) 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, 2984570 + ... + 2984903.

It is an arithmetic number, because the mean of its divisors is an integer number (250717908).

Almost surely, 2^996901991 is an apocalyptic number.

996901991 is a deficient number, since it is larger than the sum of its proper divisors (5969641).

996901991 is a wasteful number, since it uses less digits than its factorization.

996901991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5969640.

The product of its (nonzero) digits is 354294, while the sum is 53.

The square root of 996901991 is about 31573.7547814637. The cubic root of 996901991 is about 998.9662620875.

The spelling of 996901991 in words is "nine hundred ninety-six million, nine hundred one thousand, nine hundred ninety-one".