20021100021257 has 2 divisors, whose sum is σ = 20021100021258. Its totient is φ = 20021100021256.

The previous prime is 20021100021203. The next prime is 20021100021317. The reversal of 20021100021257 is 75212000112002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10726961241616 + 9294138779641 = 3275204^2 + 3048629^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021100021257 - 2⁶ = 20021100021193 is a prime.

It is a super-2 number, since 2×20021100021257² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20021102021257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010550010628 + 10010550010629.

It is an arithmetic number, because the mean of its divisors is an integer number (10010550010629).

Almost surely, 2^{20021100021257} is an apocalyptic number.

It is an amenable number.

20021100021257 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021100021257 is an equidigital number, since it uses as much as digits as its factorization.

20021100021257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 560, while the sum is 23.

Adding to 20021100021257 its reverse (75212000112002), we get a palindrome (95233100133259).

The spelling of 20021100021257 in words is "twenty trillion, twenty-one billion, one hundred million, twenty-one thousand, two hundred fifty-seven".