991541153 has 4 divisors (see below), whose sum is σ = 1007795988. Its totient is φ = 975286320.

The previous prime is 991541143. The next prime is 991541191. The reversal of 991541153 is 351145199.

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 422384704 + 569156449 = 20552^2 + 23857^2 .

It is a cyclic number.

It is not a de Polignac number, because 991541153 - 2²⁸ = 723105697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991541143) 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, 8127326 + ... + 8127447.

It is an arithmetic number, because the mean of its divisors is an integer number (251948997).

Almost surely, 2^991541153 is an apocalyptic number.

It is an amenable number.

991541153 is a deficient number, since it is larger than the sum of its proper divisors (16254835).

991541153 is a wasteful number, since it uses less digits than its factorization.

991541153 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16254834.

The product of its digits is 24300, while the sum is 38.

The square root of 991541153 is about 31488.7464501209. The cubic root of 991541153 is about 997.1723965278.

The spelling of 991541153 in words is "nine hundred ninety-one million, five hundred forty-one thousand, one hundred fifty-three".