20166220517 has 8 divisors (see below), whose sum is σ = 20669026392. Its totient is φ = 19663936000.

The previous prime is 20166220507. The next prime is 20166220541. The reversal of 20166220517 is 71502266102.

It can be written as a sum of positive squares in 4 ways, for example, as 2094526756 + 18071693761 = 45766^2 + 134431^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20166220517 - 2¹⁴ = 20166204133 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 (20166220507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51428 + ... + 207309.

It is an arithmetic number, because the mean of its divisors is an integer number (2583628299).

Almost surely, 2^20166220517 is an apocalyptic number.

It is an amenable number.

20166220517 is a deficient number, since it is larger than the sum of its proper divisors (502805875).

20166220517 is a wasteful number, since it uses less digits than its factorization.

20166220517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260679.

The product of its (nonzero) digits is 10080, while the sum is 32.

Adding to 20166220517 its reverse (71502266102), we get a palindrome (91668486619).

The spelling of 20166220517 in words is "twenty billion, one hundred sixty-six million, two hundred twenty thousand, five hundred seventeen".