33645981 has 4 divisors (see below), whose sum is σ = 44861312. Its totient is φ = 22430652.

The previous prime is 33645973. The next prime is 33646001. The reversal of 33645981 is 18954633.

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: 18954633 = 3 ⋅6318211.

It is not a de Polignac number, because 33645981 - 2³ = 33645973 is a prime.

It is a super-2 number, since 2×33645981² = 2264104074904722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33645901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5607661 + ... + 5607666.

It is an arithmetic number, because the mean of its divisors is an integer number (11215328).

Almost surely, 2^33645981 is an apocalyptic number.

It is an amenable number.

33645981 is a deficient number, since it is larger than the sum of its proper divisors (11215331).

33645981 is a wasteful number, since it uses less digits than its factorization.

33645981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11215330.

The product of its digits is 77760, while the sum is 39.

The square root of 33645981 is about 5800.5155805325. The cubic root of 33645981 is about 322.8328586633.

The spelling of 33645981 in words is "thirty-three million, six hundred forty-five thousand, nine hundred eighty-one".