72456257329 has 3 divisors (see below), whose sum is σ = 72456526507. Its totient is φ = 72455988152.

The previous prime is 72456257261. The next prime is 72456257353. The reversal of 72456257329 is 92375265427.

It is a happy number.

The square root of 72456257329 is 269177.

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: 92375265427 = 19267 ⋅4794481.

It can be written as a sum of positive squares in only one way, i.e., 8167640625 + 64288616704 = 90375^2 + 253552^2 .

It is not a de Polignac number, because 72456257329 - 2²³ = 72447868721 is a prime.

It is a super-2 number, since 2×72456257329² (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 (72456267329) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 134589 + ... + 403765.

Almost surely, 2^72456257329 is an apocalyptic number.

72456257329 is the 269177-th square number.

72456257329 is the 134589-th centered octagonal number.

It is an amenable number.

72456257329 is a deficient number, since it is larger than the sum of its proper divisors (269178).

72456257329 is an frugal number, since it uses more digits than its factorization.

72456257329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 538354 (or 269177 counting only the distinct ones).

The product of its digits is 6350400, while the sum is 52.

The spelling of 72456257329 in words is "seventy-two billion, four hundred fifty-six million, two hundred fifty-seven thousand, three hundred twenty-nine".