33991989 has 8 divisors (see below), whose sum is σ = 45469632. Its totient is φ = 22587840.

The previous prime is 33991967. The next prime is 33992003. The reversal of 33991989 is 98919933.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 33991989 - 2⁸ = 33991733 is a prime.

It is a super-2 number, since 2×33991989² = 2310910632352242, which contains 22 as substring.

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 7 ways as a sum of consecutive naturals, for example, 17284 + ... + 19149.

It is an arithmetic number, because the mean of its divisors is an integer number (5683704).

Almost surely, 2^33991989 is an apocalyptic number.

It is an amenable number.

33991989 is a deficient number, since it is larger than the sum of its proper divisors (11477643).

33991989 is a wasteful number, since it uses less digits than its factorization.

33991989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36747.

The product of its digits is 472392, while the sum is 51.

The square root of 33991989 is about 5830.2649167941. The cubic root of 33991989 is about 323.9357344722.

It can be divided in two parts, 33991 and 989, that added together give a triangular number (34980 = T₂₆₄).

The spelling of 33991989 in words is "thirty-three million, nine hundred ninety-one thousand, nine hundred eighty-nine".