81600817616 has 10 divisors (see below), whose sum is σ = 158101584162. Its totient is φ = 40800408800.

The previous prime is 81600817603. The next prime is 81600817643. The reversal of 81600817616 is 61671800618.

It can be written as a sum of positive squares in only one way, i.e., 76330638400 + 5270179216 = 276280^2 + 72596^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2550025535 + ... + 2550025566.

Almost surely, 2^81600817616 is an apocalyptic number.

It is an amenable number.

81600817616 is a deficient number, since it is larger than the sum of its proper divisors (76500766546).

81600817616 is a wasteful number, since it uses less digits than its factorization.

81600817616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5100051109 (or 5100051103 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 44.

The spelling of 81600817616 in words is "eighty-one billion, six hundred million, eight hundred seventeen thousand, six hundred sixteen".