202109 has 2 divisors, whose sum is σ = 202110. Its totient is φ = 202108.

The previous prime is 202099. The next prime is 202121. The reversal of 202109 is 901202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 178084 + 24025 = 422^2 + 155^2 .

It is a cyclic number.

It is not a de Polignac number, because 202109 - 2¹² = 198013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 202093 and 202102.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (202129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 101054 + 101055.

It is an arithmetic number, because the mean of its divisors is an integer number (101055).

2²⁰²¹⁰⁹ is an apocalyptic number.

It is an amenable number.

202109 is a deficient number, since it is larger than the sum of its proper divisors (1).

202109 is an equidigital number, since it uses as much as digits as its factorization.

202109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 202109 is about 449.5653456395. The cubic root of 202109 is about 58.6851948767.

The spelling of 202109 in words is "two hundred two thousand, one hundred nine".