391112640 has 168 divisors, whose sum is σ = 1356329520. Its totient is φ = 103440384.

The previous prime is 391112627. The next prime is 391112651. The reversal of 391112640 is 46211193.

391112640 is a `hidden beast` number, since 3 + 9 + 1 + 1 + 12 + 640 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 399832 + ... + 400808.

It is an arithmetic number, because the mean of its divisors is an integer number (8073390).

Almost surely, 2^391112640 is an apocalyptic number.

391112640 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 391112640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (678164760).

391112640 is an abundant number, since it is smaller than the sum of its proper divisors (965216880).

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

391112640 is a wasteful number, since it uses less digits than its factorization.

391112640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1139 (or 1126 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 391112640 is about 19776.5679530094. The cubic root of 391112640 is about 731.3084932390.

The spelling of 391112640 in words is "three hundred ninety-one million, one hundred twelve thousand, six hundred forty".