33981816 has 64 divisors (see below), whose sum is σ = 93703680. Its totient is φ = 10183680.

The previous prime is 33981811. The next prime is 33981821. The reversal of 33981816 is 61818933.

It is an interprime number because it is at equal distance from previous prime (33981811) and next prime (33981821).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33981811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24945 + ... + 26271.

It is an arithmetic number, because the mean of its divisors is an integer number (1464120).

Almost surely, 2^33981816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 33981816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46851840).

33981816 is an abundant number, since it is smaller than the sum of its proper divisors (59721864).

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

33981816 is a wasteful number, since it uses less digits than its factorization.

33981816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1444 (or 1440 counting only the distinct ones).

The product of its digits is 31104, while the sum is 39.

The square root of 33981816 is about 5829.3924211705. The cubic root of 33981816 is about 323.9034158080.

The spelling of 33981816 in words is "thirty-three million, nine hundred eighty-one thousand, eight hundred sixteen".