133631 has 2 divisors, whose sum is σ = 133632. Its totient is φ = 133630.

The previous prime is 133597. The next prime is 133633. The reversal of 133631 is 136331.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 133631 - 2¹⁰ = 132607 is a prime.

It is a super-2 number, since 2×133631² = 35714488322, which contains 22 as substring.

Together with 133633, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66815 + 66816.

It is an arithmetic number, because the mean of its divisors is an integer number (66816).

2¹³³⁶³¹ is an apocalyptic number.

133631 is a deficient number, since it is larger than the sum of its proper divisors (1).

133631 is an equidigital number, since it uses as much as digits as its factorization.

133631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 162, while the sum is 17.

The square root of 133631 is about 365.5557413036. Note that the first 3 decimals coincide. The cubic root of 133631 is about 51.1252846990.

Adding to 133631 its reverse (136331), we get a palindrome (269962).

The spelling of 133631 in words is "one hundred thirty-three thousand, six hundred thirty-one".