81717505148501 has 4 divisors (see below), whose sum is σ = 81720666760032. Its totient is φ = 81714343536972.

The previous prime is 81717505148497. The next prime is 81717505148581. The reversal of 81717505148501 is 10584150571718.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81717505148501 - 2² = 81717505148497 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81717505148581) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1580766995 + ... + 1580818688.

It is an arithmetic number, because the mean of its divisors is an integer number (20430166690008).

Almost surely, 2^{81717505148501} is an apocalyptic number.

It is an amenable number.

81717505148501 is a deficient number, since it is larger than the sum of its proper divisors (3161611531).

81717505148501 is a wasteful number, since it uses less digits than its factorization.

81717505148501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3161611530.

The product of its (nonzero) digits is 1568000, while the sum is 53.

The spelling of 81717505148501 in words is "eighty-one trillion, seven hundred seventeen billion, five hundred five million, one hundred forty-eight thousand, five hundred one".