8131961 has 2 divisors, whose sum is σ = 8131962. Its totient is φ = 8131960.

The previous prime is 8131957. The next prime is 8131969. The reversal of 8131961 is 1691318.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4687225 + 3444736 = 2165^2 + 1856^2 .

It is a cyclic number.

It is not a de Polignac number, because 8131961 - 2² = 8131957 is a prime.

It is a super-2 number, since 2×8131961² = 132257579411042, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (8131969) 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 as a sum of consecutive naturals, namely, 4065980 + 4065981.

It is an arithmetic number, because the mean of its divisors is an integer number (4065981).

Almost surely, 2^8131961 is an apocalyptic number.

It is an amenable number.

8131961 is a deficient number, since it is larger than the sum of its proper divisors (1).

8131961 is an equidigital number, since it uses as much as digits as its factorization.

8131961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 29.

The square root of 8131961 is about 2851.6593415063. The cubic root of 8131961 is about 201.0936833816.

The spelling of 8131961 in words is "eight million, one hundred thirty-one thousand, nine hundred sixty-one".