20406087475217 has 2 divisors, whose sum is σ = 20406087475218. Its totient is φ = 20406087475216.

The previous prime is 20406087475199. The next prime is 20406087475349. The reversal of 20406087475217 is 71257478060402.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19563141304576 + 842946170641 = 4423024^2 + 918121^2 .

It is a cyclic number.

It is not a de Polignac number, because 20406087475217 - 2⁶ = 20406087475153 is a prime.

It is not a weakly prime, because it can be changed into another prime (20406087475717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10203043737608 + 10203043737609.

It is an arithmetic number, because the mean of its divisors is an integer number (10203043737609).

Almost surely, 2^{20406087475217} is an apocalyptic number.

It is an amenable number.

20406087475217 is a deficient number, since it is larger than the sum of its proper divisors (1).

20406087475217 is an equidigital number, since it uses as much as digits as its factorization.

20406087475217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5268480, while the sum is 53.

The spelling of 20406087475217 in words is "twenty trillion, four hundred six billion, eighty-seven million, four hundred seventy-five thousand, two hundred seventeen".