33321721 has 2 divisors, whose sum is σ = 33321722. Its totient is φ = 33321720.

The previous prime is 33321709. The next prime is 33321737. The reversal of 33321721 is 12712333.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26378496 + 6943225 = 5136^2 + 2635^2 .

It is a cyclic number.

It is not a de Polignac number, because 33321721 - 2⁷ = 33321593 is a prime.

It is a super-2 number, since 2×33321721² = 2220674180803682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 33321692 and 33321701.

It is not a weakly prime, because it can be changed into another prime (33321781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16660860 + 16660861.

It is an arithmetic number, because the mean of its divisors is an integer number (16660861).

Almost surely, 2^33321721 is an apocalyptic number.

It is an amenable number.

33321721 is a deficient number, since it is larger than the sum of its proper divisors (1).

33321721 is an equidigital number, since it uses as much as digits as its factorization.

33321721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 756, while the sum is 22.

The square root of 33321721 is about 5772.4969467294. The cubic root of 33321721 is about 321.7924185794.

The spelling of 33321721 in words is "thirty-three million, three hundred twenty-one thousand, seven hundred twenty-one".