81983778704 has 20 divisors (see below), whose sum is σ = 159212131200. Its totient is φ = 40896777120.

The previous prime is 81983778683. The next prime is 81983778727. The reversal of 81983778704 is 40787738918.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5937404 + ... + 5951195.

It is an arithmetic number, because the mean of its divisors is an integer number (7960606560).

Almost surely, 2^81983778704 is an apocalyptic number.

It is an amenable number.

81983778704 is a deficient number, since it is larger than the sum of its proper divisors (77228352496).

81983778704 is a wasteful number, since it uses less digits than its factorization.

81983778704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11889038 (or 11889032 counting only the distinct ones).

The product of its (nonzero) digits is 18966528, while the sum is 62.

The spelling of 81983778704 in words is "eighty-one billion, nine hundred eighty-three million, seven hundred seventy-eight thousand, seven hundred four".