3221280 has 72 divisors (see below), whose sum is σ = 10997532. Its totient is φ = 858624.

The previous prime is 3221269. The next prime is 3221297. The reversal of 3221280 is 821223.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 3196944 + 24336 = 1788^2 + 156^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 322 + ... + 2558.

Almost surely, 2^3221280 is an apocalyptic number.

3221280 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3221280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5498766).

3221280 is an abundant number, since it is smaller than the sum of its proper divisors (7776252).

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

3221280 is a wasteful number, since it uses less digits than its factorization.

3221280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2258 (or 2247 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 3221280 is about 1794.7924671114. The cubic root of 3221280 is about 147.6871893258.

It can be divided in two parts, 32 and 21280, that added together give a palindrome (21312).

The spelling of 3221280 in words is "three million, two hundred twenty-one thousand, two hundred eighty".