33409981 has 16 divisors (see below), whose sum is σ = 39331008. Its totient is φ = 28038400.

The previous prime is 33409979. The next prime is 33409991. The reversal of 33409981 is 18990433.

It is a cyclic number.

It is not a de Polignac number, because 33409981 - 2¹ = 33409979 is a prime.

It is a super-2 number, since 2×33409981² = 2232453660840722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 33409981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33409921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8226 + ... + 11596.

It is an arithmetic number, because the mean of its divisors is an integer number (2458188).

Almost surely, 2^33409981 is an apocalyptic number.

It is an amenable number.

33409981 is a deficient number, since it is larger than the sum of its proper divisors (5921027).

33409981 is a wasteful number, since it uses less digits than its factorization.

33409981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3452.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 33409981 is about 5780.1367630879. The cubic root of 33409981 is about 322.0762810675.

It can be divided in two parts, 33 and 409981, that added together give a palindrome (410014).

The spelling of 33409981 in words is "thirty-three million, four hundred nine thousand, nine hundred eighty-one".