71243553749 has 4 divisors (see below), whose sum is σ = 71344039020. Its totient is φ = 71143068480.

The previous prime is 71243553683. The next prime is 71243553767. The reversal of 71243553749 is 94735534217.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 94735534217 = 4703 ⋅20143639.

It can be written as a sum of positive squares in 2 ways, for example, as 28961913124 + 42281640625 = 170182^2 + 205625^2 .

It is a cyclic number.

It is not a de Polignac number, because 71243553749 - 2¹² = 71243549653 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 71243553697 and 71243553706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71243553779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50241572 + ... + 50242989.

It is an arithmetic number, because the mean of its divisors is an integer number (17836009755).

Almost surely, 2^71243553749 is an apocalyptic number.

It is an amenable number.

71243553749 is a deficient number, since it is larger than the sum of its proper divisors (100485271).

71243553749 is a wasteful number, since it uses less digits than its factorization.

71243553749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100485270.

The product of its digits is 3175200, while the sum is 50.

The spelling of 71243553749 in words is "seventy-one billion, two hundred forty-three million, five hundred fifty-three thousand, seven hundred forty-nine".