133221221 has 8 divisors (see below), whose sum is σ = 158872704. Its totient is φ = 109224720.

The previous prime is 133221173. The next prime is 133221271. The reversal of 133221221 is 122122331.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 133221221 - 2²² = 129026917 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 133221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133221271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 413570 + ... + 413891.

It is an arithmetic number, because the mean of its divisors is an integer number (19859088).

Almost surely, 2^133221221 is an apocalyptic number.

It is an amenable number.

133221221 is a deficient number, since it is larger than the sum of its proper divisors (25651483).

133221221 is an equidigital number, since it uses as much as digits as its factorization.

133221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 827491.

The product of its digits is 144, while the sum is 17.

The square root of 133221221 is about 11542.1497564362. The cubic root of 133221221 is about 510.7297268799.

Adding to 133221221 its reverse (122122331), we get a palindrome (255343552).

The spelling of 133221221 in words is "one hundred thirty-three million, two hundred twenty-one thousand, two hundred twenty-one".