81680384390 has 16 divisors (see below), whose sum is σ = 160390573200. Its totient is φ = 29701957920.

The previous prime is 81680384363. The next prime is 81680384431. The reversal of 81680384390 is 9348308618.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 371274365 + ... + 371274584.

It is an arithmetic number, because the mean of its divisors is an integer number (10024410825).

Almost surely, 2^81680384390 is an apocalyptic number.

81680384390 is a deficient number, since it is larger than the sum of its proper divisors (78710188810).

81680384390 is a wasteful number, since it uses less digits than its factorization.

81680384390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 742548967.

The product of its (nonzero) digits is 995328, while the sum is 50.

The spelling of 81680384390 in words is "eighty-one billion, six hundred eighty million, three hundred eighty-four thousand, three hundred ninety".