133491331 has 2 divisors, whose sum is σ = 133491332. Its totient is φ = 133491330.

The previous prime is 133491329. The next prime is 133491341. The reversal of 133491331 is 133194331.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 133491331 - 2¹ = 133491329 is a prime.

It is a super-2 number, since 2×133491331² = 35639870904303122, which contains 22 as substring.

Together with 133491329, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 133491331.

It is not a weakly prime, because it can be changed into another prime (133491311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66745665 + 66745666.

It is an arithmetic number, because the mean of its divisors is an integer number (66745666).

Almost surely, 2^133491331 is an apocalyptic number.

133491331 is a deficient number, since it is larger than the sum of its proper divisors (1).

133491331 is an equidigital number, since it uses as much as digits as its factorization.

133491331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2916, while the sum is 28.

The square root of 133491331 is about 11553.8448578817. The cubic root of 133491331 is about 511.0746671120.

It can be divided in two parts, 1334 and 91331, that added together give a triangular number (92665 = T₄₃₀).

The spelling of 133491331 in words is "one hundred thirty-three million, four hundred ninety-one thousand, three hundred thirty-one".