391220 has 24 divisors (see below), whose sum is σ = 849408. Its totient is φ = 151200.

The previous prime is 391219. The next prime is 391231. The reversal of 391220 is 22193.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 305 + ... + 935.

It is an arithmetic number, because the mean of its divisors is an integer number (35392).

2³⁹¹²²⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 391220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (424704).

391220 is an abundant number, since it is smaller than the sum of its proper divisors (458188).

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

391220 is a wasteful number, since it uses less digits than its factorization.

391220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 671 (or 669 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 391220 is about 625.4758188771. The cubic root of 391220 is about 73.1375401583.

The spelling of 391220 in words is "three hundred ninety-one thousand, two hundred twenty".