71688447673 has 4 divisors (see below), whose sum is σ = 74160463140. Its totient is φ = 69216432208.

The previous prime is 71688447641. The next prime is 71688447707. The reversal of 71688447673 is 37674488617.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 37674488617 = 38011 ⋅991147.

It can be written as a sum of positive squares in 2 ways, for example, as 44120162304 + 27568285369 = 210048^2 + 166037^2 .

It is a cyclic number.

It is not a de Polignac number, because 71688447673 - 2⁵ = 71688447641 is a prime.

It is a super-2 number, since 2×71688447673² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71688447373) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1236007690 + ... + 1236007747.

It is an arithmetic number, because the mean of its divisors is an integer number (18540115785).

Almost surely, 2^71688447673 is an apocalyptic number.

It is an amenable number.

71688447673 is a deficient number, since it is larger than the sum of its proper divisors (2472015467).

71688447673 is a wasteful number, since it uses less digits than its factorization.

71688447673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2472015466.

The product of its digits is 37933056, while the sum is 61.

The spelling of 71688447673 in words is "seventy-one billion, six hundred eighty-eight million, four hundred forty-seven thousand, six hundred seventy-three".