81117616465 has 16 divisors (see below), whose sum is σ = 102481600320. Its totient is φ = 61468269120.

The previous prime is 81117616457. The next prime is 81117616499. The reversal of 81117616465 is 56461671118.

It is not a de Polignac number, because 81117616465 - 2³ = 81117616457 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 521307 + ... + 658783.

It is an arithmetic number, because the mean of its divisors is an integer number (6405100020).

Almost surely, 2^81117616465 is an apocalyptic number.

It is an amenable number.

81117616465 is a deficient number, since it is larger than the sum of its proper divisors (21363983855).

81117616465 is a wasteful number, since it uses less digits than its factorization.

81117616465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143712.

The product of its digits is 241920, while the sum is 46.

The spelling of 81117616465 in words is "eighty-one billion, one hundred seventeen million, six hundred sixteen thousand, four hundred sixty-five".