133291231 has 2 divisors, whose sum is σ = 133291232. Its totient is φ = 133291230.

The previous prime is 133291229. The next prime is 133291241. The reversal of 133291231 is 132192331.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 133291231 - 2¹ = 133291229 is a prime.

It is a super-2 number, since 2×133291231² = 35533104522990722, which contains 22 as substring.

Together with 133291229, it forms a pair of twin primes.

It is equal to p_7554103 and since 133291231 and 7554103 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 133291196 and 133291205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133291241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66645615 + 66645616.

It is an arithmetic number, because the mean of its divisors is an integer number (66645616).

Almost surely, 2^133291231 is an apocalyptic number.

133291231 is a deficient number, since it is larger than the sum of its proper divisors (1).

133291231 is an equidigital number, since it uses as much as digits as its factorization.

133291231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 972, while the sum is 25.

The square root of 133291231 is about 11545.1821553408. The cubic root of 133291231 is about 510.8191769096.

The spelling of 133291231 in words is "one hundred thirty-three million, two hundred ninety-one thousand, two hundred thirty-one".