33331981 has 2 divisors, whose sum is σ = 33331982. Its totient is φ = 33331980.

The previous prime is 33331979. The next prime is 33331997. The reversal of 33331981 is 18913333.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25857225 + 7474756 = 5085^2 + 2734^2 .

It is a cyclic number.

It is not a de Polignac number, because 33331981 - 2¹ = 33331979 is a prime.

It is a super-2 number, since 2×33331981² = 2222041914768722, which contains 22 as substring.

Together with 33331979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (33331481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16665990 + 16665991.

It is an arithmetic number, because the mean of its divisors is an integer number (16665991).

Almost surely, 2^33331981 is an apocalyptic number.

It is an amenable number.

33331981 is a deficient number, since it is larger than the sum of its proper divisors (1).

33331981 is an equidigital number, since it uses as much as digits as its factorization.

33331981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5832, while the sum is 31.

The square root of 33331981 is about 5773.3855752063. The cubic root of 33331981 is about 321.8254425981.

The spelling of 33331981 in words is "thirty-three million, three hundred thirty-one thousand, nine hundred eighty-one".