391920 has 80 divisors (see below), whose sum is σ = 1285632. Its totient is φ = 98560.

The previous prime is 391907. The next prime is 391921. The reversal of 391920 is 29193.

It is a happy number.

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

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5485 + ... + 5555.

2³⁹¹⁹²⁰ is an apocalyptic number.

391920 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 391920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (642816).

391920 is an abundant number, since it is smaller than the sum of its proper divisors (893712).

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

391920 is a wasteful number, since it uses less digits than its factorization.

391920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 486, while the sum is 24.

The square root of 391920 is about 626.0351427835. The cubic root of 391920 is about 73.1811352145.

The spelling of 391920 in words is "three hundred ninety-one thousand, nine hundred twenty".