21921207068611 has 2 divisors, whose sum is σ = 21921207068612. Its totient is φ = 21921207068610.

The previous prime is 21921207068591. The next prime is 21921207068617. The reversal of 21921207068611 is 11686070212912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21921207068611 - 2⁹ = 21921207068099 is a prime.

It is a super-2 number, since 2×21921207068611² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21921207068617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10960603534305 + 10960603534306.

It is an arithmetic number, because the mean of its divisors is an integer number (10960603534306).

Almost surely, 2^{21921207068611} is an apocalyptic number.

21921207068611 is a deficient number, since it is larger than the sum of its proper divisors (1).

21921207068611 is an equidigital number, since it uses as much as digits as its factorization.

21921207068611 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 46.

The spelling of 21921207068611 in words is "twenty-one trillion, nine hundred twenty-one billion, two hundred seven million, sixty-eight thousand, six hundred eleven".