72783173721 has 32 divisors (see below), whose sum is σ = 100735951360. Its totient is φ = 46709841024.

The previous prime is 72783173713. The next prime is 72783173761. The reversal of 72783173721 is 12737138727.

It is not a de Polignac number, because 72783173721 - 2³ = 72783173713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72783173761) 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 31 ways as a sum of consecutive naturals, for example, 20517870 + ... + 20521416.

It is an arithmetic number, because the mean of its divisors is an integer number (3147998480).

Almost surely, 2^72783173721 is an apocalyptic number.

It is an amenable number.

72783173721 is a deficient number, since it is larger than the sum of its proper divisors (27952777639).

72783173721 is a wasteful number, since it uses less digits than its factorization.

72783173721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5845.

The product of its digits is 691488, while the sum is 48.

The spelling of 72783173721 in words is "seventy-two billion, seven hundred eighty-three million, one hundred seventy-three thousand, seven hundred twenty-one".