391120 has 20 divisors (see below), whose sum is σ = 909540. Its totient is φ = 156416.

The previous prime is 391117. The next prime is 391133. The reversal of 391120 is 21193.

391120 = 10² + 11² + ... + 105².

It can be written as a sum of positive squares in 2 ways, for example, as 207936 + 183184 = 456^2 + 428^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 391094 and 391103.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2365 + ... + 2524.

It is an arithmetic number, because the mean of its divisors is an integer number (45477).

2³⁹¹¹²⁰ is an apocalyptic number.

It is an amenable number.

391120 is an abundant number, since it is smaller than the sum of its proper divisors (518420).

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

391120 is a wasteful number, since it uses less digits than its factorization.

391120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4902 (or 4896 counting only the distinct ones).

The product of its (nonzero) digits is 54, while the sum is 16.

The square root of 391120 is about 625.3958746266. The cubic root of 391120 is about 73.1313080491.

The spelling of 391120 in words is "three hundred ninety-one thousand, one hundred twenty".