81136630841 has 6 divisors (see below), whose sum is σ = 94383427770. Its totient is φ = 69545683536.

The previous prime is 81136630819. The next prime is 81136630849. The reversal of 81136630841 is 14803663118.

It can be written as a sum of positive squares in only one way, i.e., 70588519225 + 10548111616 = 265685^2 + 102704^2 .

It is not a de Polignac number, because 81136630841 - 2¹⁸ = 81136368697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81136630849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 827924756 + ... + 827924853.

It is an arithmetic number, because the mean of its divisors is an integer number (15730571295).

Almost surely, 2^81136630841 is an apocalyptic number.

It is an amenable number.

81136630841 is a deficient number, since it is larger than the sum of its proper divisors (13246796929).

81136630841 is a wasteful number, since it uses less digits than its factorization.

81136630841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1655849623 (or 1655849616 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 41.

The spelling of 81136630841 in words is "eighty-one billion, one hundred thirty-six million, six hundred thirty thousand, eight hundred forty-one".