21221021021117 has 2 divisors, whose sum is σ = 21221021021118. Its totient is φ = 21221021021116.

The previous prime is 21221021021099. The next prime is 21221021021183. The reversal of 21221021021117 is 71112012012212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14666709321796 + 6554311699321 = 3829714^2 + 2560139^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221021021117 - 2⁸ = 21221021020861 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21221021021092 and 21221021021101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21221021021017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610510510558 + 10610510510559.

It is an arithmetic number, because the mean of its divisors is an integer number (10610510510559).

Almost surely, 2^{21221021021117} is an apocalyptic number.

It is an amenable number.

21221021021117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221021021117 is an equidigital number, since it uses as much as digits as its factorization.

21221021021117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 224, while the sum is 23.

Adding to 21221021021117 its reverse (71112012012212), we get a palindrome (92333033033329).

The spelling of 21221021021117 in words is "twenty-one trillion, two hundred twenty-one billion, twenty-one million, twenty-one thousand, one hundred seventeen".