21213213100109 has 2 divisors, whose sum is σ = 21213213100110. Its totient is φ = 21213213100108.

The previous prime is 21213213100097. The next prime is 21213213100139. The reversal of 21213213100109 is 90100131231212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21128777526025 + 84435574084 = 4596605^2 + 290578^2 .

It is a cyclic number.

It is not a de Polignac number, because 21213213100109 - 2²⁰ = 21213212051533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21213213100139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606606550054 + 10606606550055.

It is an arithmetic number, because the mean of its divisors is an integer number (10606606550055).

Almost surely, 2^{21213213100109} is an apocalyptic number.

It is an amenable number.

21213213100109 is a deficient number, since it is larger than the sum of its proper divisors (1).

21213213100109 is an equidigital number, since it uses as much as digits as its factorization.

21213213100109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 26.

The spelling of 21213213100109 in words is "twenty-one trillion, two hundred thirteen billion, two hundred thirteen million, one hundred thousand, one hundred nine".