33011220 has 72 divisors (see below), whose sum is σ = 101620512. Its totient is φ = 8000960.

The previous prime is 33011219. The next prime is 33011239. The reversal of 33011220 is 2211033.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 33011196 and 33011205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4987 + ... + 9533.

It is an arithmetic number, because the mean of its divisors is an integer number (1411396).

Almost surely, 2^33011220 is an apocalyptic number.

33011220 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 33011220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50810256).

33011220 is an abundant number, since it is smaller than the sum of its proper divisors (68609292).

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

33011220 is a wasteful number, since it uses less digits than its factorization.

33011220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4581 (or 4568 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 12.

The square root of 33011220 is about 5745.5391391931. The cubic root of 33011220 is about 320.7897809362.

Adding to 33011220 its reverse (2211033), we get a palindrome (35222253).

The spelling of 33011220 in words is "thirty-three million, eleven thousand, two hundred twenty".