73406666681 has 2 divisors, whose sum is σ = 73406666682. Its totient is φ = 73406666680.

The previous prime is 73406666653. The next prime is 73406666741. The reversal of 73406666681 is 18666660437.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54328151056 + 19078515625 = 233084^2 + 138125^2 .

It is a cyclic number.

It is not a de Polignac number, because 73406666681 - 2²⁶ = 73339557817 is a prime.

It is a super-2 number, since 2×73406666681² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (73406666381) 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 as a sum of consecutive naturals, namely, 36703333340 + 36703333341.

It is an arithmetic number, because the mean of its divisors is an integer number (36703333341).

Almost surely, 2^73406666681 is an apocalyptic number.

It is an amenable number.

73406666681 is a deficient number, since it is larger than the sum of its proper divisors (1).

73406666681 is an equidigital number, since it uses as much as digits as its factorization.

73406666681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5225472, while the sum is 53.

The spelling of 73406666681 in words is "seventy-three billion, four hundred six million, six hundred sixty-six thousand, six hundred eighty-one".