1211000012001 has 12 divisors (see below), whose sum is σ = 1883777796628. Its totient is φ = 745230776544.

The previous prime is 1211000011997. The next prime is 1211000012017. The reversal of 1211000012001 is 1002100001121.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 784244851776 + 426755160225 = 885576^2 + 653265^2 .

It is not a de Polignac number, because 1211000012001 - 2² = 1211000011997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (1211000012021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5175213610 + ... + 5175213843.

Almost surely, 2^{1211000012001} is an apocalyptic number.

It is an amenable number.

1211000012001 is a deficient number, since it is larger than the sum of its proper divisors (672777784627).

1211000012001 is a wasteful number, since it uses less digits than its factorization.

1211000012001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10350427472 (or 10350427469 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 1211000012001 its reverse (1002100001121), we get a palindrome (2213100013122).

The spelling of 1211000012001 in words is "one trillion, two hundred eleven billion, twelve thousand, one".