23784721 has 4 divisors (see below), whose sum is σ = 23944500. Its totient is φ = 23624944.

The previous prime is 23784703. The next prime is 23784731. The reversal of 23784721 is 12748732.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13950225 + 9834496 = 3735^2 + 3136^2 .

It is a cyclic number.

It is not a de Polignac number, because 23784721 - 2¹⁷ = 23653649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23784701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79666 + ... + 79963.

It is an arithmetic number, because the mean of its divisors is an integer number (5986125).

Almost surely, 2^23784721 is an apocalyptic number.

It is an amenable number.

23784721 is a deficient number, since it is larger than the sum of its proper divisors (159779).

23784721 is a wasteful number, since it uses less digits than its factorization.

23784721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159778.

The product of its digits is 18816, while the sum is 34.

The square root of 23784721 is about 4876.9581708274. The cubic root of 23784721 is about 287.5848611495.

The spelling of 23784721 in words is "twenty-three million, seven hundred eighty-four thousand, seven hundred twenty-one".