33990921 has 20 divisors (see below), whose sum is σ = 51158800. Its totient is φ = 22490136.

The previous prime is 33990919. The next prime is 33990949. The reversal of 33990921 is 12909933.

It is not a de Polignac number, because 33990921 - 2¹ = 33990919 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 (33990961) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 9750 + ... + 12768.

It is an arithmetic number, because the mean of its divisors is an integer number (2557940).

Almost surely, 2^33990921 is an apocalyptic number.

It is an amenable number.

33990921 is a deficient number, since it is larger than the sum of its proper divisors (17167879).

33990921 is a wasteful number, since it uses less digits than its factorization.

33990921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3170 (or 3161 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 36.

The square root of 33990921 is about 5830.1733250393. The cubic root of 33990921 is about 323.9323418396.

The spelling of 33990921 in words is "thirty-three million, nine hundred ninety thousand, nine hundred twenty-one".