23705456521 has 4 divisors (see below), whose sum is σ = 23743877652. Its totient is φ = 23667035392.

The previous prime is 23705456497. The next prime is 23705456531. The reversal of 23705456521 is 12565450732.

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 6541574400 + 17163882121 = 80880^2 + 131011^2 .

It is a cyclic number.

It is not a de Polignac number, because 23705456521 - 2²³ = 23697067913 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23705456531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19209640 + ... + 19210873.

It is an arithmetic number, because the mean of its divisors is an integer number (5935969413).

Almost surely, 2^23705456521 is an apocalyptic number.

It is an amenable number.

23705456521 is a deficient number, since it is larger than the sum of its proper divisors (38421131).

23705456521 is an equidigital number, since it uses as much as digits as its factorization.

23705456521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38421130.

The product of its (nonzero) digits is 252000, while the sum is 40.

The spelling of 23705456521 in words is "twenty-three billion, seven hundred five million, four hundred fifty-six thousand, five hundred twenty-one".