33397681 has 4 divisors (see below), whose sum is σ = 33411312. Its totient is φ = 33384052.

The previous prime is 33397631. The next prime is 33397697. The reversal of 33397681 is 18679333.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18679333 = 887 ⋅21059.

It is a cyclic number.

It is not a de Polignac number, because 33397681 - 2¹⁷ = 33266609 is a prime.

It is a super-2 number, since 2×33397681² = 2230810192355522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (33397631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2011 + ... + 8416.

It is an arithmetic number, because the mean of its divisors is an integer number (8352828).

Almost surely, 2^33397681 is an apocalyptic number.

It is an amenable number.

33397681 is a deficient number, since it is larger than the sum of its proper divisors (13631).

33397681 is a wasteful number, since it uses less digits than its factorization.

33397681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13630.

The product of its digits is 81648, while the sum is 40.

The square root of 33397681 is about 5779.0726764767. The cubic root of 33397681 is about 322.0367517173.

The spelling of 33397681 in words is "thirty-three million, three hundred ninety-seven thousand, six hundred eighty-one".