33328721 has 8 divisors (see below), whose sum is σ = 35401824. Its totient is φ = 31268160.

The previous prime is 33328703. The next prime is 33328723. The reversal of 33328721 is 12782333.

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

It is a cyclic number.

It is not a de Polignac number, because 33328721 - 2¹⁴ = 33312337 is a prime.

It is a super-2 number, since 2×33328721² = 2221607286991682, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (33328723) 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, 2666 + ... + 8588.

It is an arithmetic number, because the mean of its divisors is an integer number (4425228).

Almost surely, 2^33328721 is an apocalyptic number.

It is an amenable number.

33328721 is a deficient number, since it is larger than the sum of its proper divisors (2073103).

33328721 is a wasteful number, since it uses less digits than its factorization.

33328721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6271.

The product of its digits is 6048, while the sum is 29.

The square root of 33328721 is about 5773.1032382939. The cubic root of 33328721 is about 321.8149503209.

The spelling of 33328721 in words is "thirty-three million, three hundred twenty-eight thousand, seven hundred twenty-one".