3721280 has 56 divisors (see below), whose sum is σ = 9189720. Its totient is φ = 1433600.

The previous prime is 3721279. The next prime is 3721297. The reversal of 3721280 is 821273.

It can be written as a sum of positive squares in 4 ways, for example, as 1459264 + 2262016 = 1208^2 + 1504^2 .

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9080 + ... + 9480.

Almost surely, 2^3721280 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 3721280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4594860).

3721280 is an abundant number, since it is smaller than the sum of its proper divisors (5468440).

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

3721280 is a wasteful number, since it uses less digits than its factorization.

3721280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 447 (or 437 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 3721280 is about 1929.0619482018. The cubic root of 3721280 is about 154.9639874712.

The spelling of 3721280 in words is "three million, seven hundred twenty-one thousand, two hundred eighty".