20110021111997 has 2 divisors, whose sum is σ = 20110021111998. Its totient is φ = 20110021111996.

The previous prime is 20110021111979. The next prime is 20110021112057. The reversal of 20110021111997 is 79911112001102.

Together with previous prime (20110021111979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18706758167161 + 1403262944836 = 4325131^2 + 1184594^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20110021111997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20110021111927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055010555998 + 10055010555999.

It is an arithmetic number, because the mean of its divisors is an integer number (10055010555999).

Almost surely, 2^{20110021111997} is an apocalyptic number.

It is an amenable number.

20110021111997 is a deficient number, since it is larger than the sum of its proper divisors (1).

20110021111997 is an equidigital number, since it uses as much as digits as its factorization.

20110021111997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2268, while the sum is 35.

The spelling of 20110021111997 in words is "twenty trillion, one hundred ten billion, twenty-one million, one hundred eleven thousand, nine hundred ninety-seven".