21055000097 has 2 divisors, whose sum is σ = 21055000098. Its totient is φ = 21055000096.

The previous prime is 21055000093. The next prime is 21055000159. The reversal of 21055000097 is 79000055012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16641258001 + 4413742096 = 129001^2 + 66436^2 .

It is a cyclic number.

It is not a de Polignac number, because 21055000097 - 2² = 21055000093 is a prime.

It is not a weakly prime, because it can be changed into another prime (21055000093) 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, 10527500048 + 10527500049.

It is an arithmetic number, because the mean of its divisors is an integer number (10527500049).

Almost surely, 2^21055000097 is an apocalyptic number.

It is an amenable number.

21055000097 is a deficient number, since it is larger than the sum of its proper divisors (1).

21055000097 is an equidigital number, since it uses as much as digits as its factorization.

21055000097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3150, while the sum is 29.

The spelling of 21055000097 in words is "twenty-one billion, fifty-five million, ninety-seven", and thus it is an aban number and an uban number.