201121009 has 4 divisors (see below), whose sum is σ = 201449716. Its totient is φ = 200792304.

The previous prime is 201121001. The next prime is 201121013. The reversal of 201121009 is 900121102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17247409 + 183873600 = 4153^2 + 13560^2 .

It is a cyclic number.

It is not a de Polignac number, because 201121009 - 2³ = 201121001 is a prime.

It is a super-2 number, since 2×201121009² = 80899320522356162, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201120983 and 201121001.

It is not an unprimeable number, because it can be changed into a prime (201121001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 163434 + ... + 164659.

It is an arithmetic number, because the mean of its divisors is an integer number (50362429).

Almost surely, 2^201121009 is an apocalyptic number.

It is an amenable number.

201121009 is a deficient number, since it is larger than the sum of its proper divisors (328707).

201121009 is an equidigital number, since it uses as much as digits as its factorization.

201121009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328706.

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

The square root of 201121009 is about 14181.7138950128. The cubic root of 201121009 is about 585.8941293205.

The spelling of 201121009 in words is "two hundred one million, one hundred twenty-one thousand, nine".