391968 has 36 divisors (see below), whose sum is σ = 1115478. Its totient is φ = 130560.

The previous prime is 391967. The next prime is 391987. The reversal of 391968 is 869193.

It can be written as a sum of positive squares in only one way, i.e., 374544 + 17424 = 612^2 + 132^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

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

It is not an unprimeable number, because it can be changed into a prime (391961) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 393 + ... + 968.

2³⁹¹⁹⁶⁸ is an apocalyptic number.

It is an amenable number.

391968 is an abundant number, since it is smaller than the sum of its proper divisors (723510).

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

391968 is a wasteful number, since it uses less digits than its factorization.

391968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1377 (or 1366 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 391968 is about 626.0734781158. The cubic root of 391968 is about 73.1841226874.

It can be divided in two parts, 39196 and 8, that added together give a square (39204 = 198²).

The spelling of 391968 in words is "three hundred ninety-one thousand, nine hundred sixty-eight".