23785721 has 2 divisors, whose sum is σ = 23785722. Its totient is φ = 23785720.

The previous prime is 23785693. The next prime is 23785733. The reversal of 23785721 is 12758732.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23145721 + 640000 = 4811^2 + 800^2 .

It is a cyclic number.

It is not a de Polignac number, because 23785721 - 2¹⁰ = 23784697 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (23785121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11892860 + 11892861.

It is an arithmetic number, because the mean of its divisors is an integer number (11892861).

Almost surely, 2^23785721 is an apocalyptic number.

It is an amenable number.

23785721 is a deficient number, since it is larger than the sum of its proper divisors (1).

23785721 is an equidigital number, since it uses as much as digits as its factorization.

23785721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23520, while the sum is 35.

The square root of 23785721 is about 4877.0606926714. The cubic root of 23785721 is about 287.5888914796.

It can be divided in two parts, 237 and 85721, that added together give a palindrome (85958).

The spelling of 23785721 in words is "twenty-three million, seven hundred eighty-five thousand, seven hundred twenty-one".