20211109 has 2 divisors, whose sum is σ = 20211110. Its totient is φ = 20211108.

The previous prime is 20211097. The next prime is 20211127. The reversal of 20211109 is 90111202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20205025 + 6084 = 4495^2 + 78^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211109 - 2⁵ = 20211077 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20211092 and 20211101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20211209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105554 + 10105555.

It is an arithmetic number, because the mean of its divisors is an integer number (10105555).

Almost surely, 2^20211109 is an apocalyptic number.

It is an amenable number.

20211109 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211109 is an equidigital number, since it uses as much as digits as its factorization.

20211109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 20211109 is about 4495.6767010095. The cubic root of 20211109 is about 272.3934841676.

It can be divided in two parts, 202 and 11109, that added together give a palindrome (11311).

The spelling of 20211109 in words is "twenty million, two hundred eleven thousand, one hundred nine".