72865738561 has 48 divisors (see below), whose sum is σ = 94858739712. Its totient is φ = 55321274400.

The previous prime is 72865738553. The next prime is 72865738609. The reversal of 72865738561 is 16583756827.

It is a happy number.

It is not a de Polignac number, because 72865738561 - 2³ = 72865738553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 72865738496 and 72865738505.

It is not an unprimeable number, because it can be changed into a prime (72865738061) 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 47 ways as a sum of consecutive naturals, for example, 5744256 + ... + 5756926.

It is an arithmetic number, because the mean of its divisors is an integer number (1976223744).

Almost surely, 2^72865738561 is an apocalyptic number.

It is an amenable number.

72865738561 is a deficient number, since it is larger than the sum of its proper divisors (21993001151).

72865738561 is a wasteful number, since it uses less digits than its factorization.

72865738561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12970 (or 12963 counting only the distinct ones).

The product of its digits is 16934400, while the sum is 58.

The spelling of 72865738561 in words is "seventy-two billion, eight hundred sixty-five million, seven hundred thirty-eight thousand, five hundred sixty-one".