21220575611 has 2 divisors, whose sum is σ = 21220575612. Its totient is φ = 21220575610.

The previous prime is 21220575587. The next prime is 21220575631. The reversal of 21220575611 is 11657502212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21220575611 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21220575631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610287805 + 10610287806.

It is an arithmetic number, because the mean of its divisors is an integer number (10610287806).

Almost surely, 2^21220575611 is an apocalyptic number.

21220575611 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220575611 is an equidigital number, since it uses as much as digits as its factorization.

21220575611 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8400, while the sum is 32.

The spelling of 21220575611 in words is "twenty-one billion, two hundred twenty million, five hundred seventy-five thousand, six hundred eleven".