121212009 has 6 divisors (see below), whose sum is σ = 175084026. Its totient is φ = 80808000.

The previous prime is 121211999. The next prime is 121212017. The reversal of 121212009 is 900212121.

It can be written as a sum of positive squares in only one way, i.e., 75690000 + 45522009 = 8700^2 + 6747^2 .

It is not a de Polignac number, because 121212009 - 2⁵ = 121211977 is a prime.

It is a super-2 number, since 2×121212009² = 29384702251632162, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 121211982 and 121212000.

It is not an unprimeable number, because it can be changed into a prime (121212089) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6733992 + ... + 6734009.

It is an arithmetic number, because the mean of its divisors is an integer number (29180671).

Almost surely, 2^121212009 is an apocalyptic number.

It is an amenable number.

121212009 is a deficient number, since it is larger than the sum of its proper divisors (53872017).

121212009 is a wasteful number, since it uses less digits than its factorization.

121212009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13468007 (or 13468004 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 121212009 is about 11009.6325551764. The cubic root of 121212009 is about 494.8974504428.

The spelling of 121212009 in words is "one hundred twenty-one million, two hundred twelve thousand, nine".