233309981 has 2 divisors, whose sum is σ = 233309982. Its totient is φ = 233309980.

The previous prime is 233309963. The next prime is 233309983. The reversal of 233309981 is 189903332.

233309981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 227104900 + 6205081 = 15070^2 + 2491^2 .

It is a cyclic number.

It is not a de Polignac number, because 233309981 - 2⁶ = 233309917 is a prime.

It is a super-2 number, since 2×233309981² = 108867094468440722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 233309983, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (233309983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 116654990 + 116654991.

It is an arithmetic number, because the mean of its divisors is an integer number (116654991).

Almost surely, 2^233309981 is an apocalyptic number.

It is an amenable number.

233309981 is a deficient number, since it is larger than the sum of its proper divisors (1).

233309981 is an equidigital number, since it uses as much as digits as its factorization.

233309981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34992, while the sum is 38.

The square root of 233309981 is about 15274.4879128565. The cubic root of 233309981 is about 615.6177114789.

The spelling of 233309981 in words is "two hundred thirty-three million, three hundred nine thousand, nine hundred eighty-one".