71666775645131 has 4 divisors (see below), whose sum is σ = 71931228692064. Its totient is φ = 71402322598200.

The previous prime is 71666775645103. The next prime is 71666775645139. The reversal of 71666775645131 is 13154657766617.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71666775645131 is a prime.

It is a super-2 number, since 2×71666775645131² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71666775645139) 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 in 3 ways as a sum of consecutive naturals, for example, 132226523060 + ... + 132226523601.

It is an arithmetic number, because the mean of its divisors is an integer number (17982807173016).

Almost surely, 2^{71666775645131} is an apocalyptic number.

71666775645131 is a deficient number, since it is larger than the sum of its proper divisors (264453046933).

71666775645131 is a wasteful number, since it uses less digits than its factorization.

71666775645131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264453046932.

The product of its digits is 133358400, while the sum is 65.

The spelling of 71666775645131 in words is "seventy-one trillion, six hundred sixty-six billion, seven hundred seventy-five million, six hundred forty-five thousand, one hundred thirty-one".