391891368 has 32 divisors (see below), whose sum is σ = 1068795360. Its totient is φ = 118754880.

The previous prime is 391891363. The next prime is 391891369. The reversal of 391891368 is 863198193.

It is a super-2 number, since 2×391891368² = 307157688625822848, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (391891363) 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, 741955 + ... + 742482.

It is an arithmetic number, because the mean of its divisors is an integer number (33399855).

Almost surely, 2^391891368 is an apocalyptic number.

It is an amenable number.

391891368 is an abundant number, since it is smaller than the sum of its proper divisors (676903992).

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

391891368 is a wasteful number, since it uses less digits than its factorization.

391891368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1484457 (or 1484453 counting only the distinct ones).

The product of its digits is 279936, while the sum is 48.

The square root of 391891368 is about 19796.2463108540. The cubic root of 391891368 is about 731.7935307080.

The spelling of 391891368 in words is "three hundred ninety-one million, eight hundred ninety-one thousand, three hundred sixty-eight".