13144863581 has 4 divisors (see below), whose sum is σ = 13160720700. Its totient is φ = 13129006464.

The previous prime is 13144863559. The next prime is 13144863583. The reversal of 13144863581 is 18536844131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18536844131 = 13 ⋅1425911087.

It can be written as a sum of positive squares in 2 ways, for example, as 7623036100 + 5521827481 = 87310^2 + 74309^2 .

It is a cyclic number.

It is not a de Polignac number, because 13144863581 - 2⁶ = 13144863517 is a prime.

It is a super-2 number, since 2×13144863581² (a number of 21 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 (13144863583) 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, 7927316 + ... + 7928973.

It is an arithmetic number, because the mean of its divisors is an integer number (3290180175).

Almost surely, 2^13144863581 is an apocalyptic number.

It is an amenable number.

13144863581 is a deficient number, since it is larger than the sum of its proper divisors (15857119).

13144863581 is an equidigital number, since it uses as much as digits as its factorization.

13144863581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15857118.

The product of its digits is 276480, while the sum is 44.

The spelling of 13144863581 in words is "thirteen billion, one hundred forty-four million, eight hundred sixty-three thousand, five hundred eighty-one".