21210211097 has 2 divisors, whose sum is σ = 21210211098. Its totient is φ = 21210211096.

The previous prime is 21210211051. The next prime is 21210211103. The reversal of 21210211097 is 79011201212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20855981056 + 354230041 = 144416^2 + 18821^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210211097 - 2¹² = 21210207001 is a prime.

It is not a weakly prime, because it can be changed into another prime (21210211027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605105548 + 10605105549.

It is an arithmetic number, because the mean of its divisors is an integer number (10605105549).

Almost surely, 2^21210211097 is an apocalyptic number.

It is an amenable number.

21210211097 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210211097 is an equidigital number, since it uses as much as digits as its factorization.

21210211097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 504, while the sum is 26.

The spelling of 21210211097 in words is "twenty-one billion, two hundred ten million, two hundred eleven thousand, ninety-seven".