21210003012181 has 2 divisors, whose sum is σ = 21210003012182. Its totient is φ = 21210003012180.

The previous prime is 21210003012127. The next prime is 21210003012203. The reversal of 21210003012181 is 18121030001212.

It is an a-pointer prime, because the next prime (21210003012203) can be obtained adding 21210003012181 to its sum of digits (22).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17550946678225 + 3659056333956 = 4189385^2 + 1912866^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210003012181 - 2⁴³ = 12413909989973 is a prime.

It is a super-2 number, since 2×21210003012181² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21210003012881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605001506090 + 10605001506091.

It is an arithmetic number, because the mean of its divisors is an integer number (10605001506091).

Almost surely, 2^{21210003012181} is an apocalyptic number.

It is an amenable number.

21210003012181 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210003012181 is an equidigital number, since it uses as much as digits as its factorization.

21210003012181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 22.

Adding to 21210003012181 its reverse (18121030001212), we get a palindrome (39331033013393).

The spelling of 21210003012181 in words is "twenty-one trillion, two hundred ten billion, three million, twelve thousand, one hundred eighty-one".