391063680 has 512 divisors, whose sum is σ = 1639180800. Its totient is φ = 86261760.

The previous prime is 391063679. The next prime is 391063691. The reversal of 391063680 is 86360193.

It is a happy number.

391063680 is a `hidden beast` number, since 3 + 9 + 10 + 636 + 8 + 0 = 666.

It is a super-6 number, since 6×391063680⁶ (a number of 53 digits) contains 666666 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6410850 + ... + 6410910.

It is an arithmetic number, because the mean of its divisors is an integer number (3201525).

Almost surely, 2^391063680 is an apocalyptic number.

391063680 is a gapful number since it is divisible by the number (30) 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 391063680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (819590400).

391063680 is an abundant number, since it is smaller than the sum of its proper divisors (1248117120).

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

391063680 is a wasteful number, since it uses less digits than its factorization.

391063680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 391063680 is about 19775.3300857407. The cubic root of 391063680 is about 731.2779765759.

The spelling of 391063680 in words is "three hundred ninety-one million, sixty-three thousand, six hundred eighty".