13125591 has 8 divisors (see below), whose sum is σ = 19445360. Its totient is φ = 8750376.

The previous prime is 13125569. The next prime is 13125611. The reversal of 13125591 is 19552131.

It is not a de Polignac number, because 13125591 - 2⁶ = 13125527 is a prime.

It is a super-2 number, since 2×13125591² = 344562278198562, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 486133 = 13125591 / (1 + 3 + 1 + 2 + 5 + 5 + 9 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13125551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 243040 + ... + 243093.

It is an arithmetic number, because the mean of its divisors is an integer number (2430670).

Almost surely, 2^13125591 is an apocalyptic number.

13125591 is a deficient number, since it is larger than the sum of its proper divisors (6319769).

13125591 is an equidigital number, since it uses as much as digits as its factorization.

13125591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 486142 (or 486136 counting only the distinct ones).

The product of its digits is 1350, while the sum is 27.

The square root of 13125591 is about 3622.9257513783. The cubic root of 13125591 is about 235.8882394797. Note that the first 3 decimals are identical.

It can be divided in two parts, 1312 and 5591, that added together give a triangular number (6903 = T₁₁₇).

The spelling of 13125591 in words is "thirteen million, one hundred twenty-five thousand, five hundred ninety-one".