3220720 has 40 divisors (see below), whose sum is σ = 7570944. Its totient is φ = 1274112.

The previous prime is 3220703. The next prime is 3220727. The reversal of 3220720 is 270223.

It is a happy number.

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 (16).

It is a junction number, because it is equal to n+sod(n) for n = 3220694 and 3220703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3220727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10002 + ... + 10318.

Almost surely, 2^3220720 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 3220720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3785472).

3220720 is an abundant number, since it is smaller than the sum of its proper divisors (4350224).

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

3220720 is a wasteful number, since it uses less digits than its factorization.

3220720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 457 (or 451 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 16.

The square root of 3220720 is about 1794.6364534356. The cubic root of 3220720 is about 147.6786306557.

3220720 divided by its sum of digits (16) gives a triangular number (201295 = T₆₃₄).

Adding to 3220720 its reverse (270223), we get a palindrome (3490943).

The spelling of 3220720 in words is "three million, two hundred twenty thousand, seven hundred twenty".