73218619188721 has 2 divisors, whose sum is σ = 73218619188722. Its totient is φ = 73218619188720.

The previous prime is 73218619188709. The next prime is 73218619188853. The reversal of 73218619188721 is 12788191681237.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65649517748721 + 7569101440000 = 8102439^2 + 2751200^2 .

It is a cyclic number.

It is not a de Polignac number, because 73218619188721 - 2²¹ = 73218617091569 is a prime.

It is not a weakly prime, because it can be changed into another prime (73218619588721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36609309594360 + 36609309594361.

It is an arithmetic number, because the mean of its divisors is an integer number (36609309594361).

Almost surely, 2^{73218619188721} is an apocalyptic number.

It is an amenable number.

73218619188721 is a deficient number, since it is larger than the sum of its proper divisors (1).

73218619188721 is an equidigital number, since it uses as much as digits as its factorization.

73218619188721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16257024, while the sum is 64.

The spelling of 73218619188721 in words is "seventy-three trillion, two hundred eighteen billion, six hundred nineteen million, one hundred eighty-eight thousand, seven hundred twenty-one".