71520409489 has 3 divisors (see below), whose sum is σ = 71520676923. Its totient is φ = 71520142056.

The previous prime is 71520409447. The next prime is 71520409507. The reversal of 71520409489 is 98490402517.

The square root of 71520409489 is 267433.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 98490402517 = 13 ⋅7576184809.

It can be written as a sum of positive squares in only one way, i.e., 71366451025 + 153958464 = 267145^2 + 12408^2 .

It is not a de Polignac number, because 71520409489 - 2⁷ = 71520409361 is a prime.

It is a super-2 number, since 2×71520409489² (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 (71520403489) 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 2 ways as a sum of consecutive naturals, for example, 133717 + ... + 401149.

It is an arithmetic number, because the mean of its divisors is an integer number (23840225641).

Almost surely, 2^71520409489 is an apocalyptic number.

71520409489 is the 267433-rd square number.

71520409489 is the 133717-th centered octagonal number.

It is an amenable number.

71520409489 is a deficient number, since it is larger than the sum of its proper divisors (267434).

71520409489 is an frugal number, since it uses more digits than its factorization.

71520409489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 534866 (or 267433 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 49.

Multiplying 71520409489 by its sum of digits (49), we get a square (3504500064961 = 1872031²).

The spelling of 71520409489 in words is "seventy-one billion, five hundred twenty million, four hundred nine thousand, four hundred eighty-nine".