991125541 has 8 divisors (see below), whose sum is σ = 1140984000. Its totient is φ = 843334368.

The previous prime is 991125523. The next prime is 991125587. The reversal of 991125541 is 145521199.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 991125541 - 2⁷ = 991125413 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 991125541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991122541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 515791 + ... + 517708.

It is an arithmetic number, because the mean of its divisors is an integer number (142623000).

Almost surely, 2^991125541 is an apocalyptic number.

It is an amenable number.

991125541 is a deficient number, since it is larger than the sum of its proper divisors (149858459).

991125541 is a wasteful number, since it uses less digits than its factorization.

991125541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1033643.

The product of its digits is 16200, while the sum is 37.

The square root of 991125541 is about 31482.1463848957. The cubic root of 991125541 is about 997.0330529309.

It can be divided in two parts, 99112 and 5541, that added together give a triangular number (104653 = T₄₅₇).

The spelling of 991125541 in words is "nine hundred ninety-one million, one hundred twenty-five thousand, five hundred forty-one".