72178286309 has 4 divisors (see below), whose sum is σ = 72989278380. Its totient is φ = 71367294240.

The previous prime is 72178286273. The next prime is 72178286311. The reversal of 72178286309 is 90368287127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90368287127 = 971 ⋅93067237.

It can be written as a sum of positive squares in 2 ways, for example, as 7669906084 + 64508380225 = 87578^2 + 253985^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72178286309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72178286339) 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, 405495902 + ... + 405496079.

It is an arithmetic number, because the mean of its divisors is an integer number (18247319595).

Almost surely, 2^72178286309 is an apocalyptic number.

It is an amenable number.

72178286309 is a deficient number, since it is larger than the sum of its proper divisors (810992071).

72178286309 is an equidigital number, since it uses as much as digits as its factorization.

72178286309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 810992070.

The product of its (nonzero) digits is 2032128, while the sum is 53.

The spelling of 72178286309 in words is "seventy-two billion, one hundred seventy-eight million, two hundred eighty-six thousand, three hundred nine".