33920991 has 32 divisors (see below), whose sum is σ = 54479040. Its totient is φ = 20736000.

The previous prime is 33920989. The next prime is 33921049. The reversal of 33920991 is 19902933.

It is not a de Polignac number, because 33920991 - 2¹ = 33920989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33920911) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 84391 + ... + 84791.

It is an arithmetic number, because the mean of its divisors is an integer number (1702470).

Almost surely, 2^33920991 is an apocalyptic number.

33920991 is a deficient number, since it is larger than the sum of its proper divisors (20558049).

33920991 is a wasteful number, since it uses less digits than its factorization.

33920991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664 (or 658 counting only the distinct ones).

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

The square root of 33920991 is about 5824.1729885023. The cubic root of 33920991 is about 323.7100458041.

The spelling of 33920991 in words is "thirty-three million, nine hundred twenty thousand, nine hundred ninety-one".