81537611 has 2 divisors, whose sum is σ = 81537612. Its totient is φ = 81537610.

The previous prime is 81537517. The next prime is 81537629. The reversal of 81537611 is 11673518.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81537611 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81537641) 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, 40768805 + 40768806.

It is an arithmetic number, because the mean of its divisors is an integer number (40768806).

Almost surely, 2^81537611 is an apocalyptic number.

81537611 is a deficient number, since it is larger than the sum of its proper divisors (1).

81537611 is an equidigital number, since it uses as much as digits as its factorization.

81537611 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5040, while the sum is 32.

The square root of 81537611 is about 9029.8178829919. The cubic root of 81537611 is about 433.6300070321.

The spelling of 81537611 in words is "eighty-one million, five hundred thirty-seven thousand, six hundred eleven".