33991139 has 24 divisors (see below), whose sum is σ = 42865920. Its totient is φ = 26383968.

The previous prime is 33991121. The next prime is 33991163. The reversal of 33991139 is 93119933.

33991139 = 1611² + 1612² + ... + 1623².

It is not a de Polignac number, because 33991139 - 2⁸ = 33990883 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33991189) 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, 69554 + ... + 70040.

It is an arithmetic number, because the mean of its divisors is an integer number (1786080).

Almost surely, 2^33991139 is an apocalyptic number.

33991139 is a deficient number, since it is larger than the sum of its proper divisors (8874781).

33991139 is a wasteful number, since it uses less digits than its factorization.

33991139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 579 (or 566 counting only the distinct ones).

The product of its digits is 19683, while the sum is 38.

The square root of 33991139 is about 5830.1920208515. The cubic root of 33991139 is about 323.9330343490.

The spelling of 33991139 in words is "thirty-three million, nine hundred ninety-one thousand, one hundred thirty-nine".