133819721 has 8 divisors (see below), whose sum is σ = 153220800. Its totient is φ = 114489648.

The previous prime is 133819709. The next prime is 133819723. The reversal of 133819721 is 127918331.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 133819721 - 2¹⁴ = 133803337 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (133819723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13646 + ... + 21303.

It is an arithmetic number, because the mean of its divisors is an integer number (19152600).

Almost surely, 2^133819721 is an apocalyptic number.

It is an amenable number.

133819721 is a deficient number, since it is larger than the sum of its proper divisors (19401079).

133819721 is an equidigital number, since it uses as much as digits as its factorization.

133819721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35503.

The product of its digits is 9072, while the sum is 35.

The square root of 133819721 is about 11568.0474151864. The cubic root of 133819721 is about 511.4934068504.

The spelling of 133819721 in words is "one hundred thirty-three million, eight hundred nineteen thousand, seven hundred twenty-one".