391280880 has 80 divisors (see below), whose sum is σ = 1217779200. Its totient is φ = 103928064.

The previous prime is 391280867. The next prime is 391280947. The reversal of 391280880 is 88082193.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60021 + ... + 66219.

It is an arithmetic number, because the mean of its divisors is an integer number (15222240).

Almost surely, 2^391280880 is an apocalyptic number.

391280880 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 391280880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (608889600).

391280880 is an abundant number, since it is smaller than the sum of its proper divisors (826498320).

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

391280880 is a wasteful number, since it uses less digits than its factorization.

391280880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6478 (or 6472 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 39.

The square root of 391280880 is about 19780.8210143058. The cubic root of 391280880 is about 731.4133374629.

The spelling of 391280880 in words is "three hundred ninety-one million, two hundred eighty thousand, eight hundred eighty".