81293161 has 2 divisors, whose sum is σ = 81293162. Its totient is φ = 81293160.

The previous prime is 81293141. The next prime is 81293237. The reversal of 81293161 is 16139218.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61544025 + 19749136 = 7845^2 + 4444^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81293161 is a prime.

It is not a weakly prime, because it can be changed into another prime (81293101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40646580 + 40646581.

It is an arithmetic number, because the mean of its divisors is an integer number (40646581).

Almost surely, 2^81293161 is an apocalyptic number.

It is an amenable number.

81293161 is a deficient number, since it is larger than the sum of its proper divisors (1).

81293161 is an equidigital number, since it uses as much as digits as its factorization.

81293161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 31.

The square root of 81293161 is about 9016.2720123120. The cubic root of 81293161 is about 433.1962319068.

The spelling of 81293161 in words is "eighty-one million, two hundred ninety-three thousand, one hundred sixty-one".