991537216 has 28 divisors (see below), whose sum is σ = 1992497920. Its totient is φ = 489490560.

The previous prime is 991537207. The next prime is 991537229. The reversal of 991537216 is 612735199.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93000 + ... + 103111.

It is an arithmetic number, because the mean of its divisors is an integer number (71160640).

Almost surely, 2^991537216 is an apocalyptic number.

It is an amenable number.

991537216 is an abundant number, since it is smaller than the sum of its proper divisors (1000960704).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

991537216 is a wasteful number, since it uses less digits than its factorization.

991537216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196202 (or 196192 counting only the distinct ones).

The product of its digits is 102060, while the sum is 43.

The square root of 991537216 is about 31488.6839356617. The cubic root of 991537216 is about 997.1710767396.

The spelling of 991537216 in words is "nine hundred ninety-one million, five hundred thirty-seven thousand, two hundred sixteen".