72228312785 has 4 divisors (see below), whose sum is σ = 86673975348. Its totient is φ = 57782650224.

The previous prime is 72228312721. The next prime is 72228312787. The reversal of 72228312785 is 58721382227.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58721382227 = 521 ⋅112708987.

It can be written as a sum of positive squares in 2 ways, for example, as 7634565376 + 64593747409 = 87376^2 + 254153^2 .

It is a cyclic number.

It is not a de Polignac number, because 72228312785 - 2⁶ = 72228312721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72228312787) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7222831274 + ... + 7222831283.

It is an arithmetic number, because the mean of its divisors is an integer number (21668493837).

Almost surely, 2^72228312785 is an apocalyptic number.

It is an amenable number.

72228312785 is a deficient number, since it is larger than the sum of its proper divisors (14445662563).

72228312785 is a wasteful number, since it uses less digits than its factorization.

72228312785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14445662562.

The product of its digits is 752640, while the sum is 47.

The spelling of 72228312785 in words is "seventy-two billion, two hundred twenty-eight million, three hundred twelve thousand, seven hundred eighty-five".