81688830375890 has 16 divisors (see below), whose sum is σ = 147041828772480. Its totient is φ = 32675102351280.

The previous prime is 81688830375869. The next prime is 81688830375953. The reversal of 81688830375890 is 9857303888618.

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, 52926056 + ... + 54447635.

It is an arithmetic number, because the mean of its divisors is an integer number (9190114298280).

Almost surely, 2^{81688830375890} is an apocalyptic number.

81688830375890 is a deficient number, since it is larger than the sum of its proper divisors (65352998396590).

81688830375890 is a wasteful number, since it uses less digits than its factorization.

81688830375890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107449777.

The product of its (nonzero) digits is 557383680, while the sum is 74.

The spelling of 81688830375890 in words is "eighty-one trillion, six hundred eighty-eight billion, eight hundred thirty million, three hundred seventy-five thousand, eight hundred ninety".