33981208021 has 4 divisors (see below), whose sum is σ = 35458651872. Its totient is φ = 32503764172.

The previous prime is 33981207977. The next prime is 33981208087. The reversal of 33981208021 is 12080218933.

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: 12080218933 = 89 ⋅135732797.

It is a cyclic number.

It is not a de Polignac number, because 33981208021 - 2⁷ = 33981207893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33981208621) 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 3 ways as a sum of consecutive naturals, for example, 738721891 + ... + 738721936.

It is an arithmetic number, because the mean of its divisors is an integer number (8864662968).

Almost surely, 2^33981208021 is an apocalyptic number.

It is an amenable number.

33981208021 is a deficient number, since it is larger than the sum of its proper divisors (1477443851).

33981208021 is a wasteful number, since it uses less digits than its factorization.

33981208021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1477443850.

The product of its (nonzero) digits is 20736, while the sum is 37.

The spelling of 33981208021 in words is "thirty-three billion, nine hundred eighty-one million, two hundred eight thousand, twenty-one".