13087531 has 4 divisors (see below), whose sum is σ = 13222552. Its totient is φ = 12952512.

The previous prime is 13087519. The next prime is 13087541. The reversal of 13087531 is 13578031.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13578031 = 31 ⋅438001.

It is a cyclic number.

It is not a de Polignac number, because 13087531 - 2¹¹ = 13085483 is a prime.

It is a super-2 number, since 2×13087531² = 342566935351922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13087531.

It is not an unprimeable number, because it can be changed into a prime (13087541) 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, 67365 + ... + 67558.

It is an arithmetic number, because the mean of its divisors is an integer number (3305638).

Almost surely, 2^13087531 is an apocalyptic number.

13087531 is a deficient number, since it is larger than the sum of its proper divisors (135021).

13087531 is an equidigital number, since it uses as much as digits as its factorization.

13087531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135020.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 13087531 is about 3617.6692773110. The cubic root of 13087531 is about 235.6600186937.

The spelling of 13087531 in words is "thirteen million, eighty-seven thousand, five hundred thirty-one".