81625512517 has 32 divisors (see below), whose sum is σ = 85155840000. Its totient is φ = 78203434176.

The previous prime is 81625512503. The next prime is 81625512569. The reversal of 81625512517 is 71521552618.

It is a cyclic number.

It is not a de Polignac number, because 81625512517 - 2¹⁹ = 81624988229 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 (81625512217) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 113526084 + ... + 113526802.

It is an arithmetic number, because the mean of its divisors is an integer number (2661120000).

Almost surely, 2^81625512517 is an apocalyptic number.

It is an amenable number.

81625512517 is a deficient number, since it is larger than the sum of its proper divisors (3530327483).

81625512517 is a wasteful number, since it uses less digits than its factorization.

81625512517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1153.

The product of its digits is 168000, while the sum is 43.

The spelling of 81625512517 in words is "eighty-one billion, six hundred twenty-five million, five hundred twelve thousand, five hundred seventeen".