21101020322257 has 2 divisors, whose sum is σ = 21101020322258. Its totient is φ = 21101020322256.

The previous prime is 21101020322227. The next prime is 21101020322329. The reversal of 21101020322257 is 75222302010112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19097957554641 + 2003062767616 = 4370121^2 + 1415296^2 .

It is a cyclic number.

It is not a de Polignac number, because 21101020322257 - 2⁴³ = 12304927300049 is a prime.

It is not a weakly prime, because it can be changed into another prime (21101020322227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550510161128 + 10550510161129.

It is an arithmetic number, because the mean of its divisors is an integer number (10550510161129).

Almost surely, 2^{21101020322257} is an apocalyptic number.

It is an amenable number.

21101020322257 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101020322257 is an equidigital number, since it uses as much as digits as its factorization.

21101020322257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 28.

Adding to 21101020322257 its reverse (75222302010112), we get a palindrome (96323322332369).

The spelling of 21101020322257 in words is "twenty-one trillion, one hundred one billion, twenty million, three hundred twenty-two thousand, two hundred fifty-seven".