1200001001001 has 16 divisors (see below), whose sum is σ = 1748399463360. Its totient is φ = 726046891520.

The previous prime is 1200001000987. The next prime is 1200001001011. The reversal of 1200001001001 is 1001001000021.

It is a cyclic number.

It is not a de Polignac number, because 1200001001001 - 2¹³ = 1200000992809 is a prime.

1200001001001 is a modest number, since divided by 1001001 gives 1200 as remainder.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1200001001011) 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, 30641196 + ... + 30680333.

It is an arithmetic number, because the mean of its divisors is an integer number (109274966460).

Almost surely, 2^{1200001001001} is an apocalyptic number.

1200001001001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1200001001001 is a deficient number, since it is larger than the sum of its proper divisors (548398462359).

1200001001001 is a wasteful number, since it uses less digits than its factorization.

1200001001001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61322136.

The product of its (nonzero) digits is 2, while the sum is 6.

Adding to 1200001001001 its reverse (1001001000021), we get a palindrome (2201002001022).

The spelling of 1200001001001 in words is "one trillion, two hundred billion, one million, one thousand, one".