9991968 has 48 divisors (see below), whose sum is σ = 29977920. Its totient is φ = 2854656.

The previous prime is 9991963. The next prime is 9991973. The reversal of 9991968 is 8691999.

It is an interprime number because it is at equal distance from previous prime (9991963) and next prime (9991973).

It is a tau number, because it is divible by the number of its divisors (48).

It is an Ulam number.

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 9991968.

It is not an unprimeable number, because it can be changed into a prime (9991963) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6763 + ... + 8106.

It is an arithmetic number, because the mean of its divisors is an integer number (624540).

Almost surely, 2^9991968 is an apocalyptic number.

It is an amenable number.

9991968 is an abundant number, since it is smaller than the sum of its proper divisors (19985952).

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

9991968 is a wasteful number, since it uses less digits than its factorization.

9991968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14889 (or 14881 counting only the distinct ones).

The product of its digits is 314928, while the sum is 51.

The square root of 9991968 is about 3161.0074343475. The cubic root of 9991968 is about 215.3857721550.

The spelling of 9991968 in words is "nine million, nine hundred ninety-one thousand, nine hundred sixty-eight".