33723221 has 18 divisors (see below), whose sum is σ = 41040342. Its totient is φ = 27627600.

The previous prime is 33723203. The next prime is 33723229. The reversal of 33723221 is 12232733.

It can be written as a sum of positive squares in only one way, i.e., 17522596 + 16200625 = 4186^2 + 4025^2 .

It is not a de Polignac number, because 33723221 - 2¹⁰ = 33722197 is a prime.

It is a super-2 number, since 2×33723221² = 2274511269229682, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33723229) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 25271 + ... + 26571.

It is an arithmetic number, because the mean of its divisors is an integer number (2280019).

Almost surely, 2^33723221 is an apocalyptic number.

It is an amenable number.

33723221 is a deficient number, since it is larger than the sum of its proper divisors (7317121).

33723221 is a wasteful number, since it uses less digits than its factorization.

33723221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1361 (or 1331 counting only the distinct ones).

The product of its digits is 1512, while the sum is 23.

The square root of 33723221 is about 5807.1697925926. The cubic root of 33723221 is about 323.0797088791.

Adding to 33723221 its reverse (12232733), we get a palindrome (45955954).

The spelling of 33723221 in words is "thirty-three million, seven hundred twenty-three thousand, two hundred twenty-one".