33800021 has 4 divisors (see below), whose sum is σ = 34586112. Its totient is φ = 33013932.

The previous prime is 33799999. The next prime is 33800023. The reversal of 33800021 is 12000833.

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: 12000833 = 13 ⋅923141.

It is a cyclic number.

It is not a de Polignac number, because 33800021 - 2⁶ = 33799957 is a prime.

It is a super-2 number, since 2×33800021² = 2284882839200882, 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 (33800023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 392981 + ... + 393066.

It is an arithmetic number, because the mean of its divisors is an integer number (8646528).

Almost surely, 2^33800021 is an apocalyptic number.

It is an amenable number.

33800021 is a deficient number, since it is larger than the sum of its proper divisors (786091).

33800021 is an equidigital number, since it uses as much as digits as its factorization.

33800021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 786090.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 33800021 is about 5813.7785475541. The cubic root of 33800021 is about 323.3247794764.

Adding to 33800021 its reverse (12000833), we get a palindrome (45800854).

The spelling of 33800021 in words is "thirty-three million, eight hundred thousand, twenty-one".