133421 has 4 divisors (see below), whose sum is σ = 134844. Its totient is φ = 132000.

The previous prime is 133417. The next prime is 133439. The reversal of 133421 is 124331.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 124331 = 101 ⋅1231.

It can be written as a sum of positive squares in 2 ways, for example, as 126025 + 7396 = 355^2 + 86^2 .

It is a cyclic number.

It is not a de Polignac number, because 133421 - 2² = 133417 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 133396 and 133405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 560 + ... + 761.

It is an arithmetic number, because the mean of its divisors is an integer number (33711).

2¹³³⁴²¹ is an apocalyptic number.

It is an amenable number.

133421 is a deficient number, since it is larger than the sum of its proper divisors (1423).

133421 is a wasteful number, since it uses less digits than its factorization.

133421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1422.

The product of its digits is 72, while the sum is 14.

The square root of 133421 is about 365.2683944718. The cubic root of 133421 is about 51.0984896721.

Adding to 133421 its reverse (124331), we get a palindrome (257752).

The spelling of 133421 in words is "one hundred thirty-three thousand, four hundred twenty-one".