33856921 has 4 divisors (see below), whose sum is σ = 38693632. Its totient is φ = 29020212.

The previous prime is 33856919. The next prime is 33856937. The reversal of 33856921 is 12965833.

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: 12965833 = 43 ⋅301531.

It is a cyclic number.

It is not a de Polignac number, because 33856921 - 2¹ = 33856919 is a prime.

It is a super-2 number, since 2×33856921² = 2292582199200482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (33836921) 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, 2418345 + ... + 2418358.

It is an arithmetic number, because the mean of its divisors is an integer number (9673408).

Almost surely, 2^33856921 is an apocalyptic number.

It is an amenable number.

33856921 is a deficient number, since it is larger than the sum of its proper divisors (4836711).

33856921 is an equidigital number, since it uses as much as digits as its factorization.

33856921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4836710.

The product of its digits is 38880, while the sum is 37.

The square root of 33856921 is about 5818.6700370445. The cubic root of 33856921 is about 323.5061094045.

The spelling of 33856921 in words is "thirty-three million, eight hundred fifty-six thousand, nine hundred twenty-one".