21706552211 has 2 divisors, whose sum is σ = 21706552212. Its totient is φ = 21706552210.

The previous prime is 21706552199. The next prime is 21706552267. The reversal of 21706552211 is 11225560712.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21706552211 is a prime.

It is not a weakly prime, because it can be changed into another prime (21706552711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10853276105 + 10853276106.

It is an arithmetic number, because the mean of its divisors is an integer number (10853276106).

Almost surely, 2^21706552211 is an apocalyptic number.

21706552211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21706552211 is an equidigital number, since it uses as much as digits as its factorization.

21706552211 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 21706552211 in words is "twenty-one billion, seven hundred six million, five hundred fifty-two thousand, two hundred eleven".