13161557 has 4 divisors (see below), whose sum is σ = 13181676. Its totient is φ = 13141440.

The previous prime is 13161527. The next prime is 13161583. The reversal of 13161557 is 75516131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75516131 = 5737 ⋅13163.

It can be written as a sum of positive squares in 2 ways, for example, as 9296401 + 3865156 = 3049^2 + 1966^2 .

It is a cyclic number.

It is not a de Polignac number, because 13161557 - 2⁸ = 13161301 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13161517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9044 + ... + 10397.

It is an arithmetic number, because the mean of its divisors is an integer number (3295419).

Almost surely, 2^13161557 is an apocalyptic number.

It is an amenable number.

13161557 is a deficient number, since it is larger than the sum of its proper divisors (20119).

13161557 is an equidigital number, since it uses as much as digits as its factorization.

13161557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20118.

The product of its digits is 3150, while the sum is 29.

The square root of 13161557 is about 3627.8860235680. The cubic root of 13161557 is about 236.1034988436.

Adding to 13161557 its reverse (75516131), we get a palindrome (88677688).

The spelling of 13161557 in words is "thirteen million, one hundred sixty-one thousand, five hundred fifty-seven".