133785721 has 2 divisors, whose sum is σ = 133785722. Its totient is φ = 133785720.

The previous prime is 133785709. The next prime is 133785731. The reversal of 133785721 is 127587331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 94848121 + 38937600 = 9739^2 + 6240^2 .

It is a cyclic number.

It is not a de Polignac number, because 133785721 - 2¹³ = 133777529 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (133785731) 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, 66892860 + 66892861.

It is an arithmetic number, because the mean of its divisors is an integer number (66892861).

Almost surely, 2^133785721 is an apocalyptic number.

It is an amenable number.

133785721 is a deficient number, since it is larger than the sum of its proper divisors (1).

133785721 is an equidigital number, since it uses as much as digits as its factorization.

133785721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35280, while the sum is 37.

The square root of 133785721 is about 11566.5777566227. The cubic root of 133785721 is about 511.4500842650.

The spelling of 133785721 in words is "one hundred thirty-three million, seven hundred eighty-five thousand, seven hundred twenty-one".