21203046217 has 2 divisors, whose sum is σ = 21203046218. Its totient is φ = 21203046216.

The previous prime is 21203046203. The next prime is 21203046313. The reversal of 21203046217 is 71264030212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20523714121 + 679332096 = 143261^2 + 26064^2 .

It is a cyclic number.

It is not a de Polignac number, because 21203046217 - 2⁷ = 21203046089 is a prime.

It is a super-2 number, since 2×21203046217² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21203046817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601523108 + 10601523109.

It is an arithmetic number, because the mean of its divisors is an integer number (10601523109).

Almost surely, 2^21203046217 is an apocalyptic number.

It is an amenable number.

21203046217 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203046217 is an equidigital number, since it uses as much as digits as its factorization.

21203046217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 28.

Adding to 21203046217 its reverse (71264030212), we get a palindrome (92467076429).

The spelling of 21203046217 in words is "twenty-one billion, two hundred three million, forty-six thousand, two hundred seventeen".