81106617605 has 32 divisors (see below), whose sum is σ = 107098758144. Its totient is φ = 58590233856.

The previous prime is 81106617601. The next prime is 81106617671. The reversal of 81106617605 is 50671660118.

It is a cyclic number.

It is not a de Polignac number, because 81106617605 - 2² = 81106617601 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 (81106617601) 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, 7396787 + ... + 7407743.

It is an arithmetic number, because the mean of its divisors is an integer number (3346836192).

Almost surely, 2^81106617605 is an apocalyptic number.

It is an amenable number.

81106617605 is a deficient number, since it is larger than the sum of its proper divisors (25992140539).

81106617605 is a wasteful number, since it uses less digits than its factorization.

81106617605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13445.

The product of its (nonzero) digits is 60480, while the sum is 41.

The spelling of 81106617605 in words is "eighty-one billion, one hundred six million, six hundred seventeen thousand, six hundred five".