21112100121109 has 2 divisors, whose sum is σ = 21112100121110. Its totient is φ = 21112100121108.

The previous prime is 21112100121017. The next prime is 21112100121121. The reversal of 21112100121109 is 90112100121112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18944064740484 + 2168035380625 = 4352478^2 + 1472425^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112100121109 - 2⁷ = 21112100120981 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21112100121109.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21112100121199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556050060554 + 10556050060555.

It is an arithmetic number, because the mean of its divisors is an integer number (10556050060555).

Almost surely, 2^{21112100121109} is an apocalyptic number.

It is an amenable number.

21112100121109 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112100121109 is an equidigital number, since it uses as much as digits as its factorization.

21112100121109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 22.

The spelling of 21112100121109 in words is "twenty-one trillion, one hundred twelve billion, one hundred million, one hundred twenty-one thousand, one hundred nine".