71806166505 has 24 divisors (see below), whose sum is σ = 124491077568. Its totient is φ = 38288297376.

The previous prime is 71806166501. The next prime is 71806166539. The reversal of 71806166505 is 50566160817.

71806166505 is a `hidden beast` number, since 7 + 1 + 80 + 6 + 1 + 66 + 505 = 666.

It is not a de Polignac number, because 71806166505 - 2² = 71806166501 is a prime.

It is a super-2 number, since 2×71806166505² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (71806166501) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 38734 + ... + 380936.

It is an arithmetic number, because the mean of its divisors is an integer number (5187128232).

Almost surely, 2^71806166505 is an apocalyptic number.

It is an amenable number.

71806166505 is a deficient number, since it is larger than the sum of its proper divisors (52684911063).

71806166505 is a wasteful number, since it uses less digits than its factorization.

71806166505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346877 (or 346874 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 45.

The spelling of 71806166505 in words is "seventy-one billion, eight hundred six million, one hundred sixty-six thousand, five hundred five".