333721 has 2 divisors, whose sum is σ = 333722. Its totient is φ = 333720.

The previous prime is 333719. The next prime is 333737. The reversal of 333721 is 127333.

333721 is nontrivially palindromic in base 13.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 318096 + 15625 = 564^2 + 125^2 .

It is a cyclic number.

It is not a de Polignac number, because 333721 - 2¹ = 333719 is a prime.

It is a super-2 number, since 2×333721² = 222739411682, which contains 22 as substring.

Together with 333719, it forms a pair of twin primes.

333721 is an undulating number in base 13.

333721 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (333701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166860 + 166861.

It is an arithmetic number, because the mean of its divisors is an integer number (166861).

2³³³⁷²¹ is an apocalyptic number.

It is an amenable number.

333721 is a deficient number, since it is larger than the sum of its proper divisors (1).

333721 is an equidigital number, since it uses as much as digits as its factorization.

333721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 378, while the sum is 19.

The square root of 333721 is about 577.6859008146. The cubic root of 333721 is about 69.3629963270.

The spelling of 333721 in words is "three hundred thirty-three thousand, seven hundred twenty-one".