991867968 has 336 divisors, whose sum is σ = 3550310400. Its totient is φ = 257789952.

The previous prime is 991867949. The next prime is 991867979. The reversal of 991867968 is 869768199.

It is a tau number, because it is divible by the number of its divisors (336).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6656758 + ... + 6656906.

It is an arithmetic number, because the mean of its divisors is an integer number (10566400).

Almost surely, 2^991867968 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991867968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1775155200).

991867968 is an abundant number, since it is smaller than the sum of its proper divisors (2558442432).

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

991867968 is a wasteful number, since it uses less digits than its factorization.

991867968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314 (or 301 counting only the distinct ones).

The product of its digits is 11757312, while the sum is 63.

The square root of 991867968 is about 31493.9354162035. The cubic root of 991867968 is about 997.2819415183.

The spelling of 991867968 in words is "nine hundred ninety-one million, eight hundred sixty-seven thousand, nine hundred sixty-eight".