8181931 has 2 divisors, whose sum is σ = 8181932. Its totient is φ = 8181930.

The previous prime is 8181917. The next prime is 8181937. The reversal of 8181931 is 1391818.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8181931 is a prime.

It is a super-2 number, since 2×8181931² = 133887989777522, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 8181893 and 8181902.

It is not a weakly prime, because it can be changed into another prime (8181937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4090965 + 4090966.

It is an arithmetic number, because the mean of its divisors is an integer number (4090966).

Almost surely, 2^8181931 is an apocalyptic number.

8181931 is a deficient number, since it is larger than the sum of its proper divisors (1).

8181931 is an equidigital number, since it uses as much as digits as its factorization.

8181931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 31.

The square root of 8181931 is about 2860.4074884533. The cubic root of 8181931 is about 201.5047420312.

The spelling of 8181931 in words is "eight million, one hundred eighty-one thousand, nine hundred thirty-one".