66414675581 has 2 divisors, whose sum is σ = 66414675582. Its totient is φ = 66414675580.

The previous prime is 66414675563. The next prime is 66414675631. The reversal of 66414675581 is 18557641466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36309302500 + 30105373081 = 190550^2 + 173509^2 .

It is a cyclic number.

It is not a de Polignac number, because 66414675581 - 2⁶ = 66414675517 is a prime.

It is a super-2 number, since 2×66414675581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66414672581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33207337790 + 33207337791.

It is an arithmetic number, because the mean of its divisors is an integer number (33207337791).

Almost surely, 2^66414675581 is an apocalyptic number.

It is an amenable number.

66414675581 is a deficient number, since it is larger than the sum of its proper divisors (1).

66414675581 is an equidigital number, since it uses as much as digits as its factorization.

66414675581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4838400, while the sum is 53.

The spelling of 66414675581 in words is "sixty-six billion, four hundred fourteen million, six hundred seventy-five thousand, five hundred eighty-one".