3221520 has 80 divisors (see below), whose sum is σ = 10332672. Its totient is φ = 829440.

The previous prime is 3221513. The next prime is 3221539. The reversal of 3221520 is 251223.

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

It is a super-2 number, since 2×3221520² = 20756382220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 3221520.

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, 7224 + ... + 7656.

Almost surely, 2^3221520 is an apocalyptic number.

3221520 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 3221520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5166336).

3221520 is an abundant number, since it is smaller than the sum of its proper divisors (7111152).

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

3221520 is a wasteful number, since it uses less digits than its factorization.

3221520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 480 (or 474 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 3221520 is about 1794.8593259640. The cubic root of 3221520 is about 147.6908570237.

Adding to 3221520 its reverse (251223), we get a palindrome (3472743).

It can be divided in two parts, 3221 and 520, that added together give a triangular number (3741 = T₈₆).

The spelling of 3221520 in words is "three million, two hundred twenty-one thousand, five hundred twenty".