21214204242173 has 2 divisors, whose sum is σ = 21214204242174. Its totient is φ = 21214204242172.

The previous prime is 21214204242097. The next prime is 21214204242181. The reversal of 21214204242173 is 37124240241212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20885064520324 + 329139721849 = 4570018^2 + 573707^2 .

It is a cyclic number.

It is not a de Polignac number, because 21214204242173 - 2⁸ = 21214204241917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21214204242073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10607102121086 + 10607102121087.

It is an arithmetic number, because the mean of its divisors is an integer number (10607102121087).

Almost surely, 2^{21214204242173} is an apocalyptic number.

It is an amenable number.

21214204242173 is a deficient number, since it is larger than the sum of its proper divisors (1).

21214204242173 is an equidigital number, since it uses as much as digits as its factorization.

21214204242173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43008, while the sum is 35.

Adding to 21214204242173 its reverse (37124240241212), we get a palindrome (58338444483385).

The spelling of 21214204242173 in words is "twenty-one trillion, two hundred fourteen billion, two hundred four million, two hundred forty-two thousand, one hundred seventy-three".