81223346872 has 16 divisors (see below), whose sum is σ = 158915244240. Its totient is φ = 38845948416.

The previous prime is 81223346863. The next prime is 81223346879. The reversal of 81223346872 is 27864332218.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81223346879) 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 3 ways as a sum of consecutive naturals, for example, 220715433 + ... + 220715800.

It is an arithmetic number, because the mean of its divisors is an integer number (9932202765).

Almost surely, 2^81223346872 is an apocalyptic number.

It is an amenable number.

81223346872 is a deficient number, since it is larger than the sum of its proper divisors (77691897368).

81223346872 is a wasteful number, since it uses less digits than its factorization.

81223346872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441431262 (or 441431258 counting only the distinct ones).

The product of its digits is 774144, while the sum is 46.

The spelling of 81223346872 in words is "eighty-one billion, two hundred twenty-three million, three hundred forty-six thousand, eight hundred seventy-two".