133871021 has 2 divisors, whose sum is σ = 133871022. Its totient is φ = 133871020.

The previous prime is 133870973. The next prime is 133871029. The reversal of 133871021 is 120178331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 133148521 + 722500 = 11539^2 + 850^2 .

It is a cyclic number.

It is not a de Polignac number, because 133871021 - 2²² = 129676717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133871029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66935510 + 66935511.

It is an arithmetic number, because the mean of its divisors is an integer number (66935511).

Almost surely, 2^133871021 is an apocalyptic number.

It is an amenable number.

133871021 is a deficient number, since it is larger than the sum of its proper divisors (1).

133871021 is an equidigital number, since it uses as much as digits as its factorization.

133871021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 133871021 is about 11570.2645172874. The cubic root of 133871021 is about 511.5587591001.

The spelling of 133871021 in words is "one hundred thirty-three million, eight hundred seventy-one thousand, twenty-one".