81436913761 has 16 divisors (see below), whose sum is σ = 93459041280. Its totient is φ = 69512163840.

The previous prime is 81436913759. The next prime is 81436913801. The reversal of 81436913761 is 16731963418.

It is not a de Polignac number, because 81436913761 - 2¹ = 81436913759 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81436910761) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3448185 + ... + 3471721.

It is an arithmetic number, because the mean of its divisors is an integer number (5841190080).

Almost surely, 2^81436913761 is an apocalyptic number.

It is an amenable number.

81436913761 is a deficient number, since it is larger than the sum of its proper divisors (12022127519).

81436913761 is a wasteful number, since it uses less digits than its factorization.

81436913761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25584.

The product of its digits is 653184, while the sum is 49.

The spelling of 81436913761 in words is "eighty-one billion, four hundred thirty-six million, nine hundred thirteen thousand, seven hundred sixty-one".