133309621 has 2 divisors, whose sum is σ = 133309622. Its totient is φ = 133309620.

The previous prime is 133309619. The next prime is 133309639. The reversal of 133309621 is 126903331.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 91202500 + 42107121 = 9550^2 + 6489^2 .

It is an emirp because it is prime and its reverse (126903331) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 133309621 - 2¹ = 133309619 is a prime.

Together with 133309619, 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 133309621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (133309321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66654810 + 66654811.

It is an arithmetic number, because the mean of its divisors is an integer number (66654811).

Almost surely, 2^133309621 is an apocalyptic number.

It is an amenable number.

133309621 is a deficient number, since it is larger than the sum of its proper divisors (1).

133309621 is an equidigital number, since it uses as much as digits as its factorization.

133309621 is an odious number, because the sum of its binary digits is odd.

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

The square root of 133309621 is about 11545.9785639850. The cubic root of 133309621 is about 510.8426681590.

The spelling of 133309621 in words is "one hundred thirty-three million, three hundred nine thousand, six hundred twenty-one".