81223860004 has 27 divisors (see below), whose sum is σ = 165356694993. Its totient is φ = 34808515728.

The previous prime is 81223860001. The next prime is 81223860007. The reversal of 81223860004 is 40006832218.

The square root of 81223860004 is 284998.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (81223860001) and next prime (81223860007).

It can be written as a sum of positive squares in only one way, i.e., 47423772900 + 33800087104 = 217770^2 + 183848^2 .

It is not an unprimeable number, because it can be changed into a prime (81223860001) 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 8 ways as a sum of consecutive naturals, for example, 3979794 + ... + 4000150.

Almost surely, 2^81223860004 is an apocalyptic number.

81223860004 is the 284998-th square number.

It is an amenable number.

81223860004 is an abundant number, since it is smaller than the sum of its proper divisors (84132834989).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81223860004 is an frugal number, since it uses more digits than its factorization.

81223860004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40732 (or 20366 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 34.

The spelling of 81223860004 in words is "eighty-one billion, two hundred twenty-three million, eight hundred sixty thousand, four".