81151361 has 2 divisors, whose sum is σ = 81151362. Its totient is φ = 81151360.

The previous prime is 81151351. The next prime is 81151403. The reversal of 81151361 is 16315118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74926336 + 6225025 = 8656^2 + 2495^2 .

It is a cyclic number.

It is not a de Polignac number, because 81151361 - 2⁶ = 81151297 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81151361.

It is not a weakly prime, because it can be changed into another prime (81151351) 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 as a sum of consecutive naturals, namely, 40575680 + 40575681.

It is an arithmetic number, because the mean of its divisors is an integer number (40575681).

Almost surely, 2^81151361 is an apocalyptic number.

It is an amenable number.

81151361 is a deficient number, since it is larger than the sum of its proper divisors (1).

81151361 is an equidigital number, since it uses as much as digits as its factorization.

81151361 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 720, while the sum is 26.

The square root of 81151361 is about 9008.4050197579. The cubic root of 81151361 is about 432.9442099839.

Adding to 81151361 its reverse (16315118), we get a palindrome (97466479).

The spelling of 81151361 in words is "eighty-one million, one hundred fifty-one thousand, three hundred sixty-one".