865220136722 has 18 divisors (see below), whose sum is σ = 1356758414613. Its totient is φ = 413786464872.

The previous prime is 865220136719. The next prime is 865220136797. The reversal of 865220136722 is 227631022568.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 493813992961 + 371406143761 = 702719^2 + 609431^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=657731.

It is a Duffinian number.

It is an unprimeable number.

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 8 ways as a sum of consecutive naturals, for example, 30241328 + ... + 30269924.

Almost surely, 2^865220136722 is an apocalyptic number.

865220136722 is a deficient number, since it is larger than the sum of its proper divisors (491538277891).

865220136722 is an frugal number, since it uses more digits than its factorization.

865220136722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57242 (or 28622 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 44.

The spelling of 865220136722 in words is "eight hundred sixty-five billion, two hundred twenty million, one hundred thirty-six thousand, seven hundred twenty-two".