81516011 has 2 divisors, whose sum is σ = 81516012. Its totient is φ = 81516010.

The previous prime is 81515999. The next prime is 81516041. The reversal of 81516011 is 11061518.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81516011 - 2¹⁰ = 81514987 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81516041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40758005 + 40758006.

It is an arithmetic number, because the mean of its divisors is an integer number (40758006).

Almost surely, 2^81516011 is an apocalyptic number.

81516011 is a deficient number, since it is larger than the sum of its proper divisors (1).

81516011 is an equidigital number, since it uses as much as digits as its factorization.

81516011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 23.

The square root of 81516011 is about 9028.6217663606. The cubic root of 81516011 is about 433.5917129032.

Adding to 81516011 its reverse (11061518), we get a palindrome (92577529).

The spelling of 81516011 in words is "eighty-one million, five hundred sixteen thousand, eleven".