81263127505 has 16 divisors (see below), whose sum is σ = 111452264064. Its totient is φ = 55720442880.

The previous prime is 81263127503. The next prime is 81263127527. The reversal of 81263127505 is 50572136218.

It is not a de Polignac number, because 81263127505 - 2¹ = 81263127503 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81263127503) 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, 819825 + ... + 913585.

It is an arithmetic number, because the mean of its divisors is an integer number (6965766504).

Almost surely, 2^81263127505 is an apocalyptic number.

It is an amenable number.

81263127505 is a deficient number, since it is larger than the sum of its proper divisors (30189136559).

81263127505 is a wasteful number, since it uses less digits than its factorization.

81263127505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118536.

The product of its (nonzero) digits is 100800, while the sum is 40.

The spelling of 81263127505 in words is "eighty-one billion, two hundred sixty-three million, one hundred twenty-seven thousand, five hundred five".