398720 has 64 divisors (see below), whose sum is σ = 1101600. Its totient is φ = 135168.

The previous prime is 398711. The next prime is 398729. The reversal of 398720 is 27893.

It is an interprime number because it is at equal distance from previous prime (398711) and next prime (398729).

It is a tau number, because it is divible by the number of its divisors (64).

It is a nialpdrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398729) by changing a digit.

398720 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4436 + ... + 4524.

2³⁹⁸⁷²⁰ 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 398720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (550800).

398720 is an abundant number, since it is smaller than the sum of its proper divisors (702880).

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

398720 is an equidigital number, since it uses as much as digits as its factorization.

398720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115 (or 103 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 398720 is about 631.4427923415. The cubic root of 398720 is about 73.6019533193.

The spelling of 398720 in words is "three hundred ninety-eight thousand, seven hundred twenty".