816077221682 has 18 divisors (see below), whose sum is σ = 1279698355677.
Its totient is φ = 390283748536.
The previous prime is 816077221643. The next prime is 816077221693. The reversal of 816077221682 is 286122770618.
It can be written as a sum of positive squares in 2 ways, for example, as 800611563361 + 15465658321 = 894769^2 + 124361^2
It is an ABA number since it can be written as A⋅BA, here for A=2, B=638779.
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 816077221682.
It is an unprimeable number.
It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 29369948 + ... + 29397720.
Almost surely, 2816077221682 is an apocalyptic number.
816077221682 is a deficient number, since it is larger than the sum of its proper divisors (463621133995).
816077221682 is an frugal number, since it uses more digits than its factorization.
816077221682 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 55594 (or 27798 counting only the distinct ones).
The product of its (nonzero) digits is 903168, while the sum is 50.
Multiplying 816077221682 by its sum of digits (50), we get a square (40803861084100 = 63877902).
The spelling of 816077221682 in words is "eight hundred sixteen billion, seventy-seven million, two hundred twenty-one thousand, six hundred eighty-two".