81716802645 has 16 divisors (see below), whose sum is σ = 133213807872. Its totient is φ = 42759986880.

The previous prime is 81716802641. The next prime is 81716802647. The reversal of 81716802645 is 54620861718.

It is not a de Polignac number, because 81716802645 - 2² = 81716802641 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81716802594 and 81716802603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81716802641) 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, 51393421 + ... + 51395010.

It is an arithmetic number, because the mean of its divisors is an integer number (8325862992).

Almost surely, 2^81716802645 is an apocalyptic number.

It is an amenable number.

81716802645 is a deficient number, since it is larger than the sum of its proper divisors (51497005227).

81716802645 is a wasteful number, since it uses less digits than its factorization.

81716802645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102788492.

The product of its (nonzero) digits is 645120, while the sum is 48.

The spelling of 81716802645 in words is "eighty-one billion, seven hundred sixteen million, eight hundred two thousand, six hundred forty-five".