20700021217 has 2 divisors, whose sum is σ = 20700021218. Its totient is φ = 20700021216.

The previous prime is 20700021179. The next prime is 20700021227. The reversal of 20700021217 is 71212000702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18037564416 + 2662456801 = 134304^2 + 51599^2 .

It is a cyclic number.

It is not a de Polignac number, because 20700021217 - 2³¹ = 18552537569 is a prime.

It is a super-2 number, since 2×20700021217² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20700021227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10350010608 + 10350010609.

It is an arithmetic number, because the mean of its divisors is an integer number (10350010609).

Almost surely, 2^20700021217 is an apocalyptic number.

It is an amenable number.

20700021217 is a deficient number, since it is larger than the sum of its proper divisors (1).

20700021217 is an equidigital number, since it uses as much as digits as its factorization.

20700021217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 392, while the sum is 22.

Adding to 20700021217 its reverse (71212000702), we get a palindrome (91912021919).

The spelling of 20700021217 in words is "twenty billion, seven hundred million, twenty-one thousand, two hundred seventeen".