71728419869 has 4 divisors (see below), whose sum is σ = 71995068540. Its totient is φ = 71461771200.

The previous prime is 71728419857. The next prime is 71728419901. The reversal of 71728419869 is 96891482717.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 96891482717 = 1811 ⋅53501647.

It can be written as a sum of positive squares in 2 ways, for example, as 26548791844 + 45179628025 = 162938^2 + 212555^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71728419869 is a prime.

It is a super-2 number, since 2×71728419869² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71728419809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 133323932 + ... + 133324469.

It is an arithmetic number, because the mean of its divisors is an integer number (17998767135).

Almost surely, 2^71728419869 is an apocalyptic number.

It is an amenable number.

71728419869 is a deficient number, since it is larger than the sum of its proper divisors (266648671).

71728419869 is a wasteful number, since it uses less digits than its factorization.

71728419869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266648670.

The product of its digits is 12192768, while the sum is 62.

The spelling of 71728419869 in words is "seventy-one billion, seven hundred twenty-eight million, four hundred nineteen thousand, eight hundred sixty-nine".