81968396421 has 8 divisors (see below), whose sum is σ = 111956834304. Its totient is φ = 53312778080.

The previous prime is 81968396371. The next prime is 81968396437. The reversal of 81968396421 is 12469386918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81968396421 - 2⁶ = 81968396357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81968394421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 333204741 + ... + 333204986.

It is an arithmetic number, because the mean of its divisors is an integer number (13994604288).

Almost surely, 2^81968396421 is an apocalyptic number.

It is an amenable number.

81968396421 is a deficient number, since it is larger than the sum of its proper divisors (29988437883).

81968396421 is a wasteful number, since it uses less digits than its factorization.

81968396421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 666409771.

The product of its digits is 4478976, while the sum is 57.

The spelling of 81968396421 in words is "eighty-one billion, nine hundred sixty-eight million, three hundred ninety-six thousand, four hundred twenty-one".