100220121021991 has 2 divisors, whose sum is σ = 100220121021992. Its totient is φ = 100220121021990.

The previous prime is 100220121021989. The next prime is 100220121022039. The reversal of 100220121021991 is 199120121022001.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 100220121021991 - 2¹ = 100220121021989 is a prime.

Together with 100220121021989, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100220121021931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50110060510995 + 50110060510996.

It is an arithmetic number, because the mean of its divisors is an integer number (50110060510996).

Almost surely, 2^{100220121021991} is an apocalyptic number.

100220121021991 is a deficient number, since it is larger than the sum of its proper divisors (1).

100220121021991 is an equidigital number, since it uses as much as digits as its factorization.

100220121021991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 31.

Adding to 100220121021991 its reverse (199120121022001), we get a palindrome (299340242043992).

The spelling of 100220121021991 in words is "one hundred trillion, two hundred twenty billion, one hundred twenty-one million, twenty-one thousand, nine hundred ninety-one".