33740721 has 24 divisors (see below), whose sum is σ = 56114240. Its totient is φ = 19136736.

The previous prime is 33740719. The next prime is 33740809. The reversal of 33740721 is 12704733.

It is not a de Polignac number, because 33740721 - 2¹ = 33740719 is a prime.

It is a super-2 number, since 2×33740721² = 2276872507199682, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (33740321) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6831 + ... + 10683.

Almost surely, 2^33740721 is an apocalyptic number.

It is an amenable number.

33740721 is a deficient number, since it is larger than the sum of its proper divisors (22373519).

33740721 is a wasteful number, since it uses less digits than its factorization.

33740721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4005 (or 4002 counting only the distinct ones).

The product of its (nonzero) digits is 3528, while the sum is 27.

The square root of 33740721 is about 5808.6763552465. The cubic root of 33740721 is about 323.1355844947.

The spelling of 33740721 in words is "thirty-three million, seven hundred forty thousand, seven hundred twenty-one".