81208180875 has 16 divisors (see below), whose sum is σ = 135130413600. Its totient is φ = 43311029600.

The previous prime is 81208180873. The next prime is 81208180883. The reversal of 81208180875 is 57808180218.

It is not a de Polignac number, because 81208180875 - 2¹ = 81208180873 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81208180873) 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, 108277200 + ... + 108277949.

It is an arithmetic number, because the mean of its divisors is an integer number (8445650850).

Almost surely, 2^81208180875 is an apocalyptic number.

81208180875 is a deficient number, since it is larger than the sum of its proper divisors (53922232725).

81208180875 is a wasteful number, since it uses less digits than its factorization.

81208180875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216555167 (or 216555157 counting only the distinct ones).

The product of its (nonzero) digits is 286720, while the sum is 48.

The spelling of 81208180875 in words is "eighty-one billion, two hundred eight million, one hundred eighty thousand, eight hundred seventy-five".