21067684241 has 2 divisors, whose sum is σ = 21067684242. Its totient is φ = 21067684240.

The previous prime is 21067684193. The next prime is 21067684273. The reversal of 21067684241 is 14248676012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16945530625 + 4122153616 = 130175^2 + 64204^2 .

It is a cyclic number.

It is not a de Polignac number, because 21067684241 - 2²⁶ = 21000575377 is a prime.

It is not a weakly prime, because it can be changed into another prime (21067624241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10533842120 + 10533842121.

It is an arithmetic number, because the mean of its divisors is an integer number (10533842121).

Almost surely, 2^21067684241 is an apocalyptic number.

It is an amenable number.

21067684241 is a deficient number, since it is larger than the sum of its proper divisors (1).

21067684241 is an equidigital number, since it uses as much as digits as its factorization.

21067684241 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 129024, while the sum is 41.

The spelling of 21067684241 in words is "twenty-one billion, sixty-seven million, six hundred eighty-four thousand, two hundred forty-one".