5131681 has 4 divisors (see below), whose sum is σ = 5202052. Its totient is φ = 5061312.

The previous prime is 5131673. The next prime is 5131697. The reversal of 5131681 is 1861315.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1861315 = 5 ⋅372263.

It can be written as a sum of positive squares in 2 ways, for example, as 3389281 + 1742400 = 1841^2 + 1320^2 .

It is a cyclic number.

It is not a de Polignac number, because 5131681 - 2³ = 5131673 is a prime.

It is a super-2 number, since 2×5131681² = 52668299771522, which contains 22 as substring.

It is a Duffinian number.

5131681 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (5131631) 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, 35076 + ... + 35221.

It is an arithmetic number, because the mean of its divisors is an integer number (1300513).

Almost surely, 2^5131681 is an apocalyptic number.

It is an amenable number.

5131681 is a deficient number, since it is larger than the sum of its proper divisors (70371).

5131681 is an equidigital number, since it uses as much as digits as its factorization.

5131681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70370.

The product of its digits is 720, while the sum is 25.

The square root of 5131681 is about 2265.3213900019. The cubic root of 5131681 is about 172.4857483150.

Adding to 5131681 its reverse (1861315), we get a palindrome (6992996).

The spelling of 5131681 in words is "five million, one hundred thirty-one thousand, six hundred eighty-one".