81610776976 has 15 divisors (see below), whose sum is σ = 158123094411. Its totient is φ = 40804817136.

The previous prime is 81610776943. The next prime is 81610776983. The reversal of 81610776976 is 67967701618.

The square root of 81610776976 is 285676.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81610776976.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1106995 + ... + 1178413.

Almost surely, 2^81610776976 is an apocalyptic number.

81610776976 is the 285676-th square number.

It is an amenable number.

81610776976 is a deficient number, since it is larger than the sum of its proper divisors (76512317435).

81610776976 is an frugal number, since it uses more digits than its factorization.

81610776976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142846 (or 71421 counting only the distinct ones).

The product of its (nonzero) digits is 5334336, while the sum is 58.

The spelling of 81610776976 in words is "eighty-one billion, six hundred ten million, seven hundred seventy-six thousand, nine hundred seventy-six".