391879680 has 176 divisors, whose sum is σ = 1295407104. Its totient is φ = 101007360.

The previous prime is 391879679. The next prime is 391879703. The reversal of 391879680 is 86978193.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 475749 + ... + 476571.

Almost surely, 2^391879680 is an apocalyptic number.

391879680 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 391879680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (647703552).

391879680 is an abundant number, since it is smaller than the sum of its proper divisors (903527424).

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

391879680 is a wasteful number, since it uses less digits than its factorization.

391879680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 882 (or 864 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 51.

The square root of 391879680 is about 19795.9511011722. The cubic root of 391879680 is about 731.7862554880.

The spelling of 391879680 in words is "three hundred ninety-one million, eight hundred seventy-nine thousand, six hundred eighty".