133213021 has 4 divisors (see below), whose sum is σ = 133236252. Its totient is φ = 133189792.

The previous prime is 133212949. The next prime is 133213043. The reversal of 133213021 is 120312331.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 120312331 = 173 ⋅695447.

It can be written as a sum of positive squares in 2 ways, for example, as 63824121 + 69388900 = 7989^2 + 8330^2 .

It is a cyclic number.

It is not a de Polignac number, because 133213021 - 2²¹ = 131115869 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 133212986 and 133213004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133213051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3855 + ... + 16771.

It is an arithmetic number, because the mean of its divisors is an integer number (33309063).

Almost surely, 2^133213021 is an apocalyptic number.

It is an amenable number.

133213021 is a deficient number, since it is larger than the sum of its proper divisors (23231).

133213021 is a wasteful number, since it uses less digits than its factorization.

133213021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23230.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 133213021 is about 11541.7945311810. The cubic root of 133213021 is about 510.7192478945.

Adding to 133213021 its reverse (120312331), we get a palindrome (253525352).

The spelling of 133213021 in words is "one hundred thirty-three million, two hundred thirteen thousand, twenty-one".