1200120009 has 16 divisors (see below), whose sum is σ = 1837505280. Its totient is φ = 689063760.

The previous prime is 1200120007. The next prime is 1200120011. The reversal of 1200120009 is 9000210021.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1200120007) and next prime (1200120011).

It is not a de Polignac number, because 1200120009 - 2¹ = 1200120007 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1200120009.

It is not an unprimeable number, because it can be changed into a prime (1200120007) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 956407 + ... + 957660.

It is an arithmetic number, because the mean of its divisors is an integer number (114844080).

Almost surely, 2^1200120009 is an apocalyptic number.

1200120009 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

1200120009 is a deficient number, since it is larger than the sum of its proper divisors (637385271).

1200120009 is a wasteful number, since it uses less digits than its factorization.

1200120009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1914100.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 1200120009 is about 34642.7482887833. The cubic root of 1200120009 is about 1062.6939926107.

The spelling of 1200120009 in words is "one billion, two hundred million, one hundred twenty thousand, nine".