13581557 has 4 divisors (see below), whose sum is σ = 14816256. Its totient is φ = 12346860.

The previous prime is 13581527. The next prime is 13581559. The reversal of 13581557 is 75518531.

13581557 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 13581557 - 2⁶ = 13581493 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 (13581559) 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, 617333 + ... + 617354.

It is an arithmetic number, because the mean of its divisors is an integer number (3704064).

Almost surely, 2^13581557 is an apocalyptic number.

It is an amenable number.

13581557 is a deficient number, since it is larger than the sum of its proper divisors (1234699).

13581557 is a wasteful number, since it uses less digits than its factorization.

13581557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1234698.

The product of its digits is 21000, while the sum is 35.

The square root of 13581557 is about 3685.3164043268. The cubic root of 13581557 is about 238.5886905035.

The spelling of 13581557 in words is "thirteen million, five hundred eighty-one thousand, five hundred fifty-seven".