81143921243 has 32 divisors (see below), whose sum is σ = 106870510080. Its totient is φ = 59687712000.

The previous prime is 81143921239. The next prime is 81143921249. The reversal of 81143921243 is 34212934118.

It is not a de Polignac number, because 81143921243 - 2² = 81143921239 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81143921197 and 81143921206.

It is not an unprimeable number, because it can be changed into a prime (81143921249) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 312413 + ... + 509793.

It is an arithmetic number, because the mean of its divisors is an integer number (3339703440).

Almost surely, 2^81143921243 is an apocalyptic number.

81143921243 is a deficient number, since it is larger than the sum of its proper divisors (25726588837).

81143921243 is a wasteful number, since it uses less digits than its factorization.

81143921243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197699.

The product of its digits is 41472, while the sum is 38.

The spelling of 81143921243 in words is "eighty-one billion, one hundred forty-three million, nine hundred twenty-one thousand, two hundred forty-three".