308720 has 40 divisors (see below), whose sum is σ = 763344. Its totient is φ = 115712.

The previous prime is 308713. The next prime is 308723. The reversal of 308720 is 27803.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 308692 and 308701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (308723) by changing a digit.

308720 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, 1247 + ... + 1473.

2³⁰⁸⁷²⁰ 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 308720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (381672).

308720 is an abundant number, since it is smaller than the sum of its proper divisors (454624).

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

308720 is a wasteful number, since it uses less digits than its factorization.

308720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257 (or 251 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 308720 is about 555.6257733403. The cubic root of 308720 is about 67.5857164364.

The spelling of 308720 in words is "three hundred eight thousand, seven hundred twenty".