133005721 has 4 divisors (see below), whose sum is σ = 134377012. Its totient is φ = 131634432.

The previous prime is 133005709. The next prime is 133005727. The reversal of 133005721 is 127500331.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 37650496 + 95355225 = 6136^2 + 9765^2 .

It is not a de Polignac number, because 133005721 - 2¹⁵ = 132972953 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 133005692 and 133005701.

It is not an unprimeable number, because it can be changed into a prime (133005727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 685500 + ... + 685693.

It is an arithmetic number, because the mean of its divisors is an integer number (33594253).

Almost surely, 2^133005721 is an apocalyptic number.

It is an amenable number.

133005721 is a deficient number, since it is larger than the sum of its proper divisors (1371291).

133005721 is an equidigital number, since it uses as much as digits as its factorization.

133005721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1371290.

The product of its (nonzero) digits is 630, while the sum is 22.

The square root of 133005721 is about 11532.8106288103. The cubic root of 133005721 is about 510.4541910590.

The spelling of 133005721 in words is "one hundred thirty-three million, five thousand, seven hundred twenty-one".