816131 has 2 divisors, whose sum is σ = 816132. Its totient is φ = 816130.

The previous prime is 816121. The next prime is 816133. The reversal of 816131 is 131618.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-816131 is a prime.

It is a super-2 number, since 2×816131² = 1332139618322, which contains 22 as substring.

Together with 816133, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (816133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408065 + 408066.

It is an arithmetic number, because the mean of its divisors is an integer number (408066).

2⁸¹⁶¹³¹ is an apocalyptic number.

816131 is a deficient number, since it is larger than the sum of its proper divisors (1).

816131 is an equidigital number, since it uses as much as digits as its factorization.

816131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 144, while the sum is 20.

The square root of 816131 is about 903.3996900597. The cubic root of 816131 is about 93.4515749128.

Adding to 816131 its reverse (131618), we get a palindrome (947749).

It can be divided in two parts, 8161 and 31, that added together give a 13-th power (8192 = 2¹³).

The spelling of 816131 in words is "eight hundred sixteen thousand, one hundred thirty-one".