991216002 has 48 divisors (see below), whose sum is σ = 2335340160. Its totient is φ = 279613152.

The previous prime is 991215913. The next prime is 991216021. The reversal of 991216002 is 200612199.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1888 + ... + 44564.

It is an arithmetic number, because the mean of its divisors is an integer number (48652920).

Almost surely, 2^991216002 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991216002, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1167670080).

991216002 is an abundant number, since it is smaller than the sum of its proper divisors (1344124158).

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

991216002 is a wasteful number, since it uses less digits than its factorization.

991216002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42775 (or 42768 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 991216002 is about 31483.5830553004. The cubic root of 991216002 is about 997.0633854029.

The spelling of 991216002 in words is "nine hundred ninety-one million, two hundred sixteen thousand, two".