133540021 has 4 divisors (see below), whose sum is σ = 134424544. Its totient is φ = 132655500.

The previous prime is 133540013. The next prime is 133540031. The reversal of 133540021 is 120045331.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 133540021 - 2³ = 133540013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133540031) 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, 442035 + ... + 442336.

It is an arithmetic number, because the mean of its divisors is an integer number (33606136).

Almost surely, 2^133540021 is an apocalyptic number.

It is an amenable number.

133540021 is a deficient number, since it is larger than the sum of its proper divisors (884523).

133540021 is an equidigital number, since it uses as much as digits as its factorization.

133540021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 884522.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 133540021 is about 11555.9517565625. The cubic root of 133540021 is about 511.1367964915.

Adding to 133540021 its reverse (120045331), we get a palindrome (253585352).

The spelling of 133540021 in words is "one hundred thirty-three million, five hundred forty thousand, twenty-one".