21401212213 has 2 divisors, whose sum is σ = 21401212214. Its totient is φ = 21401212212.

The previous prime is 21401212207. The next prime is 21401212271. The reversal of 21401212213 is 31221210412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20184737329 + 1216474884 = 142073^2 + 34878^2 .

It is a cyclic number.

It is not a de Polignac number, because 21401212213 - 2²⁵ = 21367657781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21401210213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10700606106 + 10700606107.

It is an arithmetic number, because the mean of its divisors is an integer number (10700606107).

Almost surely, 2^21401212213 is an apocalyptic number.

It is an amenable number.

21401212213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21401212213 is an equidigital number, since it uses as much as digits as its factorization.

21401212213 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 19.

Adding to 21401212213 its reverse (31221210412), we get a palindrome (52622422625).

The spelling of 21401212213 in words is "twenty-one billion, four hundred one million, two hundred twelve thousand, two hundred thirteen".