133220321 has 16 divisors (see below), whose sum is σ = 149037504. Its totient is φ = 118286784.

The previous prime is 133220293. The next prime is 133220327. The reversal of 133220321 is 123022331.

It is a cyclic number.

It is not a de Polignac number, because 133220321 - 2²⁶ = 66111457 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 133220321.

It is not an unprimeable number, because it can be changed into a prime (133220327) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35675 + ... + 39231.

It is an arithmetic number, because the mean of its divisors is an integer number (9314844).

Almost surely, 2^133220321 is an apocalyptic number.

It is an amenable number.

133220321 is a deficient number, since it is larger than the sum of its proper divisors (15817183).

133220321 is a wasteful number, since it uses less digits than its factorization.

133220321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3680.

The product of its (nonzero) digits is 216, while the sum is 17.

The square root of 133220321 is about 11542.1107688325. The cubic root of 133220321 is about 510.7285767684.

Adding to 133220321 its reverse (123022331), we get a palindrome (256242652).

The spelling of 133220321 in words is "one hundred thirty-three million, two hundred twenty thousand, three hundred twenty-one".