121312009 has 32 divisors (see below), whose sum is σ = 153812736. Its totient is φ = 93139200.

The previous prime is 121312007. The next prime is 121312013. The reversal of 121312009 is 900213121.

It is not a de Polignac number, because 121312009 - 2¹ = 121312007 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121312001) 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 31 ways as a sum of consecutive naturals, for example, 615699 + ... + 615895.

It is an arithmetic number, because the mean of its divisors is an integer number (4806648).

Almost surely, 2^121312009 is an apocalyptic number.

It is an amenable number.

121312009 is a deficient number, since it is larger than the sum of its proper divisors (32500727).

121312009 is a wasteful number, since it uses less digits than its factorization.

121312009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 385.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 121312009 is about 11014.1730965152. The cubic root of 121312009 is about 495.0335099581.

The spelling of 121312009 in words is "one hundred twenty-one million, three hundred twelve thousand, nine".