20011212197 has 2 divisors, whose sum is σ = 20011212198. Its totient is φ = 20011212196.

The previous prime is 20011212191. The next prime is 20011212241. The reversal of 20011212197 is 79121211002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13717328641 + 6293883556 = 117121^2 + 79334^2 .

It is a cyclic number.

It is not a de Polignac number, because 20011212197 - 2²² = 20007017893 is a prime.

It is a super-2 number, since 2×20011212197² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20011212191) 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, 10005606098 + 10005606099.

It is an arithmetic number, because the mean of its divisors is an integer number (10005606099).

Almost surely, 2^20011212197 is an apocalyptic number.

It is an amenable number.

20011212197 is a deficient number, since it is larger than the sum of its proper divisors (1).

20011212197 is an equidigital number, since it uses as much as digits as its factorization.

20011212197 is an odious number, because the sum of its binary digits is odd.

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

Adding to 20011212197 its reverse (79121211002), we get a palindrome (99132423199).

The spelling of 20011212197 in words is "twenty billion, eleven million, two hundred twelve thousand, one hundred ninety-seven".