1209921109 has 8 divisors (see below), whose sum is σ = 1221346368. Its totient is φ = 1198529280.

The previous prime is 1209921101. The next prime is 1209921131. The reversal of 1209921109 is 9011299021.

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 1209921109 - 2³ = 1209921101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1209921101) 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, 67584 + ... + 83590.

It is an arithmetic number, because the mean of its divisors is an integer number (152668296).

Almost surely, 2^1209921109 is an apocalyptic number.

It is an amenable number.

1209921109 is a deficient number, since it is larger than the sum of its proper divisors (11425259).

1209921109 is a wasteful number, since it uses less digits than its factorization.

1209921109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16715.

The product of its (nonzero) digits is 2916, while the sum is 34.

The square root of 1209921109 is about 34783.9202649730. The cubic root of 1209921109 is about 1065.5790774682.

The spelling of 1209921109 in words is "one billion, two hundred nine million, nine hundred twenty-one thousand, one hundred nine".