81157734587 has 2 divisors, whose sum is σ = 81157734588. Its totient is φ = 81157734586.

The previous prime is 81157734517. The next prime is 81157734629. The reversal of 81157734587 is 78543775118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81157734587 - 2⁸ = 81157734331 is a prime.

It is not a weakly prime, because it can be changed into another prime (81157734517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40578867293 + 40578867294.

It is an arithmetic number, because the mean of its divisors is an integer number (40578867294).

Almost surely, 2^81157734587 is an apocalyptic number.

81157734587 is a deficient number, since it is larger than the sum of its proper divisors (1).

81157734587 is an equidigital number, since it uses as much as digits as its factorization.

81157734587 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6585600, while the sum is 56.

The spelling of 81157734587 in words is "eighty-one billion, one hundred fifty-seven million, seven hundred thirty-four thousand, five hundred eighty-seven".