81446460209 has 2 divisors, whose sum is σ = 81446460210. Its totient is φ = 81446460208.

The previous prime is 81446460127. The next prime is 81446460211. The reversal of 81446460209 is 90206464418.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 73755696400 + 7690763809 = 271580^2 + 87697^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81446460209 is a prime.

Together with 81446460211, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81446460209.

It is not a weakly prime, because it can be changed into another prime (81446460289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40723230104 + 40723230105.

It is an arithmetic number, because the mean of its divisors is an integer number (40723230105).

Almost surely, 2^81446460209 is an apocalyptic number.

It is an amenable number.

81446460209 is a deficient number, since it is larger than the sum of its proper divisors (1).

81446460209 is an equidigital number, since it uses as much as digits as its factorization.

81446460209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 331776, while the sum is 44.

The spelling of 81446460209 in words is "eighty-one billion, four hundred forty-six million, four hundred sixty thousand, two hundred nine".