13005857 has 4 divisors (see below), whose sum is σ = 13140036. Its totient is φ = 12871680.

The previous prime is 13005767. The next prime is 13005859. The reversal of 13005857 is 75850031.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75850031 = 887 ⋅85513.

It can be written as a sum of positive squares in 2 ways, for example, as 4426816 + 8579041 = 2104^2 + 2929^2 .

It is a cyclic number.

It is not a de Polignac number, because 13005857 - 2¹⁰ = 13004833 is a prime.

It is a super-4 number, since 4×13005857⁴ (a number of 30 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13005859) 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, 66944 + ... + 67137.

It is an arithmetic number, because the mean of its divisors is an integer number (3285009).

Almost surely, 2^13005857 is an apocalyptic number.

It is an amenable number.

13005857 is a deficient number, since it is larger than the sum of its proper divisors (134179).

13005857 is an equidigital number, since it uses as much as digits as its factorization.

13005857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134178.

The product of its (nonzero) digits is 4200, while the sum is 29.

The square root of 13005857 is about 3606.3634037629. The cubic root of 13005857 is about 235.1687756940.

Adding to 13005857 its reverse (75850031), we get a palindrome (88855888).

The spelling of 13005857 in words is "thirteen million, five thousand, eight hundred fifty-seven".