20011021210997 has 2 divisors, whose sum is σ = 20011021210998. Its totient is φ = 20011021210996.

The previous prime is 20011021210987. The next prime is 20011021211011. The reversal of 20011021210997 is 79901212011002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16163181959716 + 3847839251281 = 4020346^2 + 1961591^2 .

It is a cyclic number.

It is not a de Polignac number, because 20011021210997 - 2⁶ = 20011021210933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20011021210927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10005510605498 + 10005510605499.

It is an arithmetic number, because the mean of its divisors is an integer number (10005510605499).

Almost surely, 2^{20011021210997} is an apocalyptic number.

It is an amenable number.

20011021210997 is a deficient number, since it is larger than the sum of its proper divisors (1).

20011021210997 is an equidigital number, since it uses as much as digits as its factorization.

20011021210997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4536, while the sum is 35.

Adding to 20011021210997 its reverse (79901212011002), we get a palindrome (99912233221999).

The spelling of 20011021210997 in words is "twenty trillion, eleven billion, twenty-one million, two hundred ten thousand, nine hundred ninety-seven".