3221840 has 80 divisors (see below), whose sum is σ = 8356608. Its totient is φ = 1148928.

The previous prime is 3221819. The next prime is 3221899. The reversal of 3221840 is 481223.

It is a tau number, because it is divible by the number of its divisors (80).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31229 + ... + 31331.

Almost surely, 2^3221840 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 3221840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4178304).

3221840 is an abundant number, since it is smaller than the sum of its proper divisors (5134768).

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

3221840 is a wasteful number, since it uses less digits than its factorization.

3221840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156 (or 150 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 3221840 is about 1794.9484672268. The cubic root of 3221840 is about 147.6957470041.

The spelling of 3221840 in words is "three million, two hundred twenty-one thousand, eight hundred forty".