23855661581 has 2 divisors, whose sum is σ = 23855661582. Its totient is φ = 23855661580.

The previous prime is 23855661517. The next prime is 23855661589. The reversal of 23855661581 is 18516655832.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22220672356 + 1634989225 = 149066^2 + 40435^2 .

It is a cyclic number.

It is not a de Polignac number, because 23855661581 - 2⁶ = 23855661517 is a prime.

It is a super-2 number, since 2×23855661581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23855661589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11927830790 + 11927830791.

It is an arithmetic number, because the mean of its divisors is an integer number (11927830791).

Almost surely, 2^23855661581 is an apocalyptic number.

It is an amenable number.

23855661581 is a deficient number, since it is larger than the sum of its proper divisors (1).

23855661581 is an equidigital number, since it uses as much as digits as its factorization.

23855661581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728000, while the sum is 50.

The spelling of 23855661581 in words is "twenty-three billion, eight hundred fifty-five million, six hundred sixty-one thousand, five hundred eighty-one".