391234866 has 48 divisors (see below), whose sum is σ = 863104032. Its totient is φ = 118138240.

The previous prime is 391234843. The next prime is 391234897. The reversal of 391234866 is 668432193.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 251146 + ... + 252698.

It is an arithmetic number, because the mean of its divisors is an integer number (17981334).

Almost surely, 2^391234866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 391234866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (431552016).

391234866 is an abundant number, since it is smaller than the sum of its proper divisors (471869166).

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

391234866 is a wasteful number, since it uses less digits than its factorization.

391234866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1927 (or 1916 counting only the distinct ones).

The product of its digits is 186624, while the sum is 42.

The square root of 391234866 is about 19779.6578837957. The cubic root of 391234866 is about 731.3846653296.

The spelling of 391234866 in words is "three hundred ninety-one million, two hundred thirty-four thousand, eight hundred sixty-six".