991076646 has 96 divisors (see below), whose sum is σ = 2371783680. Its totient is φ = 275184000.

The previous prime is 991076623. The next prime is 991076683. The reversal of 991076646 is 646670199.

It is a junction number, because it is equal to n+sod(n) for n = 991076595 and 991076604.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 1648746 + ... + 1649346.

It is an arithmetic number, because the mean of its divisors is an integer number (24706080).

Almost surely, 2^991076646 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991076646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1185891840).

991076646 is an abundant number, since it is smaller than the sum of its proper divisors (1380707034).

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

991076646 is a wasteful number, since it uses less digits than its factorization.

991076646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 770 (or 763 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 48.

The square root of 991076646 is about 31481.3698240721. The cubic root of 991076646 is about 997.0166571832.

The spelling of 991076646 in words is "nine hundred ninety-one million, seventy-six thousand, six hundred forty-six".