20021128397 has 2 divisors, whose sum is σ = 20021128398. Its totient is φ = 20021128396.

The previous prime is 20021128363. The next prime is 20021128399. The reversal of 20021128397 is 79382112002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12478900681 + 7542227716 = 111709^2 + 86846^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021128397 - 2¹² = 20021124301 is a prime.

Together with 20021128399, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20021128399) 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, 10010564198 + 10010564199.

It is an arithmetic number, because the mean of its divisors is an integer number (10010564199).

Almost surely, 2^20021128397 is an apocalyptic number.

It is an amenable number.

20021128397 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021128397 is an equidigital number, since it uses as much as digits as its factorization.

20021128397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 35.

The spelling of 20021128397 in words is "twenty billion, twenty-one million, one hundred twenty-eight thousand, three hundred ninety-seven".