20812002109 has 2 divisors, whose sum is σ = 20812002110. Its totient is φ = 20812002108.

The previous prime is 20812002103. The next prime is 20812002139. The reversal of 20812002109 is 90120021802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12089002500 + 8722999609 = 109950^2 + 93397^2 .

It is a cyclic number.

It is not a de Polignac number, because 20812002109 - 2¹¹ = 20812000061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20812002103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10406001054 + 10406001055.

It is an arithmetic number, because the mean of its divisors is an integer number (10406001055).

Almost surely, 2^20812002109 is an apocalyptic number.

It is an amenable number.

20812002109 is a deficient number, since it is larger than the sum of its proper divisors (1).

20812002109 is an equidigital number, since it uses as much as digits as its factorization.

20812002109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 25.

The spelling of 20812002109 in words is "twenty billion, eight hundred twelve million, two thousand, one hundred nine".