33991020 has 144 divisors (see below), whose sum is σ = 120294720. Its totient is φ = 7607808.

The previous prime is 33991003. The next prime is 33991051. The reversal of 33991020 is 2019933.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 66526 + ... + 67034.

It is an arithmetic number, because the mean of its divisors is an integer number (835380).

Almost surely, 2^33991020 is an apocalyptic number.

33991020 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 33991020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60147360).

33991020 is an abundant number, since it is smaller than the sum of its proper divisors (86303700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

33991020 is a wasteful number, since it uses less digits than its factorization.

33991020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 584 (or 579 counting only the distinct ones).

The product of its (nonzero) digits is 1458, while the sum is 27.

The square root of 33991020 is about 5830.1818153468. The cubic root of 33991020 is about 323.9326563282.

The spelling of 33991020 in words is "thirty-three million, nine hundred ninety-one thousand, twenty".