33991990 has 16 divisors (see below), whose sum is σ = 61342560. Its totient is φ = 13561920.

The previous prime is 33991967. The next prime is 33992003. The reversal of 33991990 is 9919933.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66 + ... + 8245.

It is an arithmetic number, because the mean of its divisors is an integer number (3833910).

Almost surely, 2^33991990 is an apocalyptic number.

33991990 is a deficient number, since it is larger than the sum of its proper divisors (27350570).

33991990 is a wasteful number, since it uses less digits than its factorization.

33991990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8727.

The product of its (nonzero) digits is 59049, while the sum is 43.

The square root of 33991990 is about 5830.2650025535. The cubic root of 33991990 is about 323.9357376488.

It can be divided in two parts, 339 and 91990, that added together give a palindrome (92329).

The spelling of 33991990 in words is "thirty-three million, nine hundred ninety-one thousand, nine hundred ninety".