81895508001217 has 16 divisors (see below), whose sum is σ = 89371169880192. Its totient is φ = 74729932680960.

The previous prime is 81895508001211. The next prime is 81895508001247. The reversal of 81895508001217 is 71210080559818.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81895508001217 - 2¹¹ = 81895507999169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81895508001211) 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, 229856509 + ... + 230212522.

It is an arithmetic number, because the mean of its divisors is an integer number (5585698117512).

Almost surely, 2^{81895508001217} is an apocalyptic number.

It is an amenable number.

81895508001217 is a deficient number, since it is larger than the sum of its proper divisors (7475661878975).

81895508001217 is a wasteful number, since it uses less digits than its factorization.

81895508001217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460069368.

The product of its (nonzero) digits is 1612800, while the sum is 55.

The spelling of 81895508001217 in words is "eighty-one trillion, eight hundred ninety-five billion, five hundred eight million, one thousand, two hundred seventeen".