391687344 has 180 divisors, whose sum is σ = 1207442808. Its totient is φ = 118056960.

The previous prime is 391687343. The next prime is 391687363. The reversal of 391687344 is 443786193.

Its product of digits (435456) is a multiple of the sum of its prime divisors (126).

It is a self number, because there is not a number n which added to its sum of digits gives 391687344.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391687343) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 6421074 + ... + 6421134.

Almost surely, 2^391687344 is an apocalyptic number.

391687344 is a gapful number since it is divisible by the number (34) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 391687344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (603721404).

391687344 is an abundant number, since it is smaller than the sum of its proper divisors (815755464).

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

391687344 is a wasteful number, since it uses less digits than its factorization.

391687344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196 (or 126 counting only the distinct ones).

The product of its digits is 435456, while the sum is 45.

The square root of 391687344 is about 19791.0925418482. The cubic root of 391687344 is about 731.6665147602. Note that the first 3 decimals are identical.

The spelling of 391687344 in words is "three hundred ninety-one million, six hundred eighty-seven thousand, three hundred forty-four".