391099968 has 336 divisors, whose sum is σ = 1389888000. Its totient is φ = 107412480.

The previous prime is 391099949. The next prime is 391099987. The reversal of 391099968 is 869990193.

It is an interprime number because it is at equal distance from previous prime (391099949) and next prime (391099987).

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 (54).

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, 2624758 + ... + 2624906.

Almost surely, 2^391099968 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 391099968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (694944000).

391099968 is an abundant number, since it is smaller than the sum of its proper divisors (998788032).

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

391099968 is a wasteful number, since it uses less digits than its factorization.

391099968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215 (or 192 counting only the distinct ones).

The product of its (nonzero) digits is 944784, while the sum is 54.

The square root of 391099968 is about 19776.2475712659. The cubic root of 391099968 is about 731.3005950528.

The spelling of 391099968 in words is "three hundred ninety-one million, ninety-nine thousand, nine hundred sixty-eight".