33605981 has 2 divisors, whose sum is σ = 33605982. Its totient is φ = 33605980.

The previous prime is 33605969. The next prime is 33606011. The reversal of 33605981 is 18950633.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32376100 + 1229881 = 5690^2 + 1109^2 .

It is a cyclic number.

It is not a de Polignac number, because 33605981 - 2¹⁴ = 33589597 is a prime.

It is a super-2 number, since 2×33605981² = 2258723917944722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (33605881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16802990 + 16802991.

It is an arithmetic number, because the mean of its divisors is an integer number (16802991).

Almost surely, 2^33605981 is an apocalyptic number.

It is an amenable number.

33605981 is a deficient number, since it is larger than the sum of its proper divisors (1).

33605981 is an equidigital number, since it uses as much as digits as its factorization.

33605981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 33605981 is about 5797.0665857828. The cubic root of 33605981 is about 322.7048747291.

The spelling of 33605981 in words is "thirty-three million, six hundred five thousand, nine hundred eighty-one".