21000222012173 has 2 divisors, whose sum is σ = 21000222012174. Its totient is φ = 21000222012172.

The previous prime is 21000222012169. The next prime is 21000222012223. The reversal of 21000222012173 is 37121022200012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13998837216004 + 7001384796169 = 3741502^2 + 2646013^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000222012173 - 2² = 21000222012169 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000222012163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500111006086 + 10500111006087.

It is an arithmetic number, because the mean of its divisors is an integer number (10500111006087).

Almost surely, 2^{21000222012173} is an apocalyptic number.

It is an amenable number.

21000222012173 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000222012173 is an equidigital number, since it uses as much as digits as its factorization.

21000222012173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 23.

Adding to 21000222012173 its reverse (37121022200012), we get a palindrome (58121244212185).

The spelling of 21000222012173 in words is "twenty-one trillion, two hundred twenty-two million, twelve thousand, one hundred seventy-three".