23523506581 has 4 divisors (see below), whose sum is σ = 23523813964. Its totient is φ = 23523199200.

The previous prime is 23523506579. The next prime is 23523506593. The reversal of 23523506581 is 18560532532.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 6088680900 + 17434825681 = 78030^2 + 132041^2 .

It is a cyclic number.

It is not a de Polignac number, because 23523506581 - 2¹ = 23523506579 is a prime.

It is a super-2 number, since 2×23523506581² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23523506561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62041 + ... + 225601.

It is an arithmetic number, because the mean of its divisors is an integer number (5880953491).

Almost surely, 2^23523506581 is an apocalyptic number.

It is an amenable number.

23523506581 is a deficient number, since it is larger than the sum of its proper divisors (307383).

23523506581 is a wasteful number, since it uses less digits than its factorization.

23523506581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 307382.

The product of its (nonzero) digits is 216000, while the sum is 40.

The spelling of 23523506581 in words is "twenty-three billion, five hundred twenty-three million, five hundred six thousand, five hundred eighty-one".