33720320 has 96 divisors (see below), whose sum is σ = 84029400. Its totient is φ = 12976128.

The previous prime is 33720287. The next prime is 33720331. The reversal of 33720320 is 2302733.

It can be written as a sum of positive squares in 4 ways, for example, as 28558336 + 5161984 = 5344^2 + 2272^2 .

It is a super-2 number, since 2×33720320² = 2274119961804800, which contains 22 as substring.

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 = 33720292 and 33720301.

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, 378836 + ... + 378924.

Almost surely, 2^33720320 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 33720320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42014700).

33720320 is an abundant number, since it is smaller than the sum of its proper divisors (50309080).

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

33720320 is an equidigital number, since it uses as much as digits as its factorization.

33720320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153 (or 133 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 20.

The square root of 33720320 is about 5806.9200097814. The cubic root of 33720320 is about 323.0704444308.

The spelling of 33720320 in words is "thirty-three million, seven hundred twenty thousand, three hundred twenty".