121021009 has 4 divisors (see below), whose sum is σ = 126282816. Its totient is φ = 115759204.

The previous prime is 121021007. The next prime is 121021037. The reversal of 121021009 is 900120121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 121021009 - 2¹ = 121021007 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121020983 and 121021001.

It is not an unprimeable number, because it can be changed into a prime (121021003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2630869 + ... + 2630914.

It is an arithmetic number, because the mean of its divisors is an integer number (31570704).

Almost surely, 2^121021009 is an apocalyptic number.

It is an amenable number.

121021009 is a deficient number, since it is larger than the sum of its proper divisors (5261807).

121021009 is an equidigital number, since it uses as much as digits as its factorization.

121021009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5261806.

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

The square root of 121021009 is about 11000.9549130973. The cubic root of 121021009 is about 494.6373686603.

The spelling of 121021009 in words is "one hundred twenty-one million, twenty-one thousand, nine".