1200001021011 has 24 divisors (see below), whose sum is σ = 1883793671760. Its totient is φ = 731687276736.

The previous prime is 1200001020997. The next prime is 1200001021019. The reversal of 1200001021011 is 1101201000021.

It is a happy number.

It is not a de Polignac number, because 1200001021011 - 2¹⁷ = 1200000889939 is a prime.

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

It is a junction number, because it is equal to n+sod(n) for n = 1200001020984 and 1200001021002.

It is not an unprimeable number, because it can be changed into a prime (1200001021019) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 47035041 + ... + 47060546.

It is an arithmetic number, because the mean of its divisors is an integer number (78491402990).

Almost surely, 2^{1200001021011} is an apocalyptic number.

1200001021011 is a deficient number, since it is larger than the sum of its proper divisors (683792650749).

1200001021011 is a wasteful number, since it uses less digits than its factorization.

1200001021011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94095715 (or 94095712 counting only the distinct ones).

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

Adding to 1200001021011 its reverse (1101201000021), we get a palindrome (2301202021032).

The spelling of 1200001021011 in words is "one trillion, two hundred billion, one million, twenty-one thousand, eleven".