5131561 has 4 divisors (see below), whose sum is σ = 5146452. Its totient is φ = 5116672.

The previous prime is 5131543. The next prime is 5131571. The reversal of 5131561 is 1651315.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1638400 + 3493161 = 1280^2 + 1869^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5131561 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (5131541) 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, 6916 + ... + 7621.

It is an arithmetic number, because the mean of its divisors is an integer number (1286613).

Almost surely, 2^5131561 is an apocalyptic number.

It is an amenable number.

5131561 is a deficient number, since it is larger than the sum of its proper divisors (14891).

5131561 is a wasteful number, since it uses less digits than its factorization.

5131561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14890.

The product of its digits is 450, while the sum is 22.

The square root of 5131561 is about 2265.2949035391. The cubic root of 5131561 is about 172.4844038269.

Adding to 5131561 its reverse (1651315), we get a palindrome (6782876).

The spelling of 5131561 in words is "five million, one hundred thirty-one thousand, five hundred sixty-one".