991864953 has 8 divisors (see below), whose sum is σ = 1469429600. Its totient is φ = 661243284.

The previous prime is 991864921. The next prime is 991864963. The reversal of 991864953 is 359468199.

It is not a de Polignac number, because 991864953 - 2⁵ = 991864921 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 991864953.

It is not an unprimeable number, because it can be changed into a prime (991864963) 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 7 ways as a sum of consecutive naturals, for example, 18367843 + ... + 18367896.

It is an arithmetic number, because the mean of its divisors is an integer number (183678700).

Almost surely, 2^991864953 is an apocalyptic number.

It is an amenable number.

991864953 is a deficient number, since it is larger than the sum of its proper divisors (477564647).

991864953 is a wasteful number, since it uses less digits than its factorization.

991864953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36735748 (or 36735742 counting only the distinct ones).

The product of its digits is 2099520, while the sum is 54.

The square root of 991864953 is about 31493.8875498088. The cubic root of 991864953 is about 997.2809310316.

The spelling of 991864953 in words is "nine hundred ninety-one million, eight hundred sixty-four thousand, nine hundred fifty-three".