3643220 has 48 divisors (see below), whose sum is σ = 8926848. Its totient is φ = 1223040.

The previous prime is 3643217. The next prime is 3643267. The reversal of 3643220 is 223463.

3643220 = T₆₉ + T₇₀ + ... + T₂₈₀.

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

It is a junction number, because it is equal to n+sod(n) for n = 3643192 and 3643201.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7175 + ... + 7665.

It is an arithmetic number, because the mean of its divisors is an integer number (185976).

Almost surely, 2^3643220 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 3643220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4463424).

3643220 is an abundant number, since it is smaller than the sum of its proper divisors (5283628).

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

3643220 is a wasteful number, since it uses less digits than its factorization.

3643220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 560 (or 558 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 20.

The square root of 3643220 is about 1908.7220855850. The cubic root of 3643220 is about 153.8727796224.

Adding to 3643220 its reverse (223463), we get a palindrome (3866683).

The spelling of 3643220 in words is "three million, six hundred forty-three thousand, two hundred twenty".