21101200997 has 2 divisors, whose sum is σ = 21101200998. Its totient is φ = 21101200996.

The previous prime is 21101200979. The next prime is 21101201039. The reversal of 21101200997 is 79900210112.

Together with previous prime (21101200979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21096400516 + 4800481 = 145246^2 + 2191^2 .

It is a cyclic number.

It is not a de Polignac number, because 21101200997 - 2²⁴ = 21084423781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21101200927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550600498 + 10550600499.

It is an arithmetic number, because the mean of its divisors is an integer number (10550600499).

Almost surely, 2^21101200997 is an apocalyptic number.

It is an amenable number.

21101200997 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101200997 is an equidigital number, since it uses as much as digits as its factorization.

21101200997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2268, while the sum is 32.

The spelling of 21101200997 in words is "twenty-one billion, one hundred one million, two hundred thousand, nine hundred ninety-seven".