133784921 has 2 divisors, whose sum is σ = 133784922. Its totient is φ = 133784920.

The previous prime is 133784899. The next prime is 133784923. The reversal of 133784921 is 129487331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 133633600 + 151321 = 11560^2 + 389^2 .

It is a cyclic number.

It is not a de Polignac number, because 133784921 - 2⁶ = 133784857 is a prime.

Together with 133784923, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (133784923) 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 as a sum of consecutive naturals, namely, 66892460 + 66892461.

It is an arithmetic number, because the mean of its divisors is an integer number (66892461).

Almost surely, 2^133784921 is an apocalyptic number.

It is an amenable number.

133784921 is a deficient number, since it is larger than the sum of its proper divisors (1).

133784921 is an equidigital number, since it uses as much as digits as its factorization.

133784921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 38.

The square root of 133784921 is about 11566.5431741727. The cubic root of 133784921 is about 511.4490648216.

The spelling of 133784921 in words is "one hundred thirty-three million, seven hundred eighty-four thousand, nine hundred twenty-one".