636122645651665 has 16 divisors (see below), whose sum is σ = 766172480057856. Its totient is φ = 507014621467200.

The previous prime is 636122645651659. The next prime is 636122645651681. The reversal of 636122645651665 is 566156546221636.

It is a happy number.

It is not a de Polignac number, because 636122645651665 - 2³⁹ = 635572889837777 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 636122645651597 and 636122645651606.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 121365955 + ... + 126498775.

It is an arithmetic number, because the mean of its divisors is an integer number (47885780003616).

Almost surely, 2^{636122645651665} is an apocalyptic number.

It is an amenable number.

636122645651665 is a deficient number, since it is larger than the sum of its proper divisors (130049834406191).

636122645651665 is a wasteful number, since it uses less digits than its factorization.

636122645651665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5224560.

The product of its digits is 279936000, while the sum is 64.

The spelling of 636122645651665 in words is "six hundred thirty-six trillion, one hundred twenty-two billion, six hundred forty-five million, six hundred fifty-one thousand, six hundred sixty-five".