21100097 has 2 divisors, whose sum is σ = 21100098. Its totient is φ = 21100096.

The previous prime is 21100087. The next prime is 21100103. The reversal of 21100097 is 79000112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11669056 + 9431041 = 3416^2 + 3071^2 .

It is a cyclic number.

It is not a de Polignac number, because 21100097 - 2⁶ = 21100033 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21100007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550048 + 10550049.

It is an arithmetic number, because the mean of its divisors is an integer number (10550049).

Almost surely, 2^21100097 is an apocalyptic number.

It is an amenable number.

21100097 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100097 is an equidigital number, since it uses as much as digits as its factorization.

21100097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 126, while the sum is 20.

The square root of 21100097 is about 4593.4841895886. The cubic root of 21100097 is about 276.3300722684.

The spelling of 21100097 in words is "twenty-one million, one hundred thousand, ninety-seven".