20021080109 has 2 divisors, whose sum is σ = 20021080110. Its totient is φ = 20021080108.

The previous prime is 20021080103. The next prime is 20021080111. The reversal of 20021080109 is 90108012002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19950150025 + 70930084 = 141245^2 + 8422^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021080109 - 2¹² = 20021076013 is a prime.

Together with 20021080111, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20021080103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010540054 + 10010540055.

It is an arithmetic number, because the mean of its divisors is an integer number (10010540055).

Almost surely, 2^20021080109 is an apocalyptic number.

It is an amenable number.

20021080109 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021080109 is an equidigital number, since it uses as much as digits as its factorization.

20021080109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 23.

The spelling of 20021080109 in words is "twenty billion, twenty-one million, eighty thousand, one hundred nine".