81851967853 has 8 divisors (see below), whose sum is σ = 85514548608. Its totient is φ = 78198037104.

The previous prime is 81851967793. The next prime is 81851967881. The reversal of 81851967853 is 35876915818.

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 81851967853 - 2¹³ = 81851959661 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81851967791 and 81851967800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81851967553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2143150 + ... + 2181007.

It is an arithmetic number, because the mean of its divisors is an integer number (10689318576).

Almost surely, 2^81851967853 is an apocalyptic number.

It is an amenable number.

81851967853 is a deficient number, since it is larger than the sum of its proper divisors (3662580755).

81851967853 is a wasteful number, since it uses less digits than its factorization.

81851967853 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4325003.

The product of its digits is 14515200, while the sum is 61.

The spelling of 81851967853 in words is "eighty-one billion, eight hundred fifty-one million, nine hundred sixty-seven thousand, eight hundred fifty-three".