618217186026661 has 16 divisors (see below), whose sum is σ = 666187783254000. Its totient is φ = 570306009581568.

The previous prime is 618217186026631. The next prime is 618217186026667. The reversal of 618217186026661 is 166620681712816.

It can be written as a sum of positive squares in 8 ways, for example, as 32102479469025 + 586114706557636 = 5665905^2 + 24209806^2 .

It is not a de Polignac number, because 618217186026661 - 2¹⁹ = 618217185502373 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 618217186026661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (618217186026667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 200225595 + ... + 203289751.

It is an arithmetic number, because the mean of its divisors is an integer number (41636736453375).

Almost surely, 2^{618217186026661} is an apocalyptic number.

It is an amenable number.

618217186026661 is a deficient number, since it is larger than the sum of its proper divisors (47970597227339).

618217186026661 is a wasteful number, since it uses less digits than its factorization.

618217186026661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3073848.

The product of its (nonzero) digits is 13934592, while the sum is 61.

The spelling of 618217186026661 in words is "six hundred eighteen trillion, two hundred seventeen billion, one hundred eighty-six million, twenty-six thousand, six hundred sixty-one".