21101020021097 has 2 divisors, whose sum is σ = 21101020021098. Its totient is φ = 21101020021096.

The previous prime is 21101020021079. The next prime is 21101020021121. The reversal of 21101020021097 is 79012002010112.

Together with previous prime (21101020021079) 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., 20817127131241 + 283892889856 = 4562579^2 + 532816^2 .

It is a cyclic number.

It is not a de Polignac number, because 21101020021097 - 2¹² = 21101020017001 is a prime.

It is not a weakly prime, because it can be changed into another prime (21101020021397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550510010548 + 10550510010549.

It is an arithmetic number, because the mean of its divisors is an integer number (10550510010549).

Almost surely, 2^{21101020021097} is an apocalyptic number.

It is an amenable number.

21101020021097 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101020021097 is an equidigital number, since it uses as much as digits as its factorization.

21101020021097 is an evil number, because the sum of its binary digits is even.

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

The spelling of 21101020021097 in words is "twenty-one trillion, one hundred one billion, twenty million, twenty-one thousand, ninety-seven".