1210121209 has 8 divisors (see below), whose sum is σ = 1320388128. Its totient is φ = 1099896960.

The previous prime is 1210121203. The next prime is 1210121221. The reversal of 1210121209 is 9021210121.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1210121209 - 2³ = 1210121201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1210121201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89929 + ... + 102505.

It is an arithmetic number, because the mean of its divisors is an integer number (165048516).

Almost surely, 2^1210121209 is an apocalyptic number.

It is an amenable number.

1210121209 is a deficient number, since it is larger than the sum of its proper divisors (110266919).

1210121209 is a wasteful number, since it uses less digits than its factorization.

1210121209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21335.

The product of its (nonzero) digits is 72, while the sum is 19.

The square root of 1210121209 is about 34786.7964750996. The cubic root of 1210121209 is about 1065.6378170060.

It can be divided in two parts, 121012 and 1209, that added together give a palindrome (122221).

The spelling of 1210121209 in words is "one billion, two hundred ten million, one hundred twenty-one thousand, two hundred nine".