1200001211021 has 4 divisors (see below), whose sum is σ = 1200033388092. Its totient is φ = 1199969033952.

The previous prime is 1200001211011. The next prime is 1200001211039. The reversal of 1200001211021 is 1201121000021.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 626329788100 + 573671422921 = 791410^2 + 757411^2 .

It is a cyclic number.

It is not a de Polignac number, because 1200001211021 - 2³⁴ = 1182821341837 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1200001210993 and 1200001211011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1200001211011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16032530 + ... + 16107203.

It is an arithmetic number, because the mean of its divisors is an integer number (300008347023).

Almost surely, 2^{1200001211021} is an apocalyptic number.

It is an amenable number.

1200001211021 is a deficient number, since it is larger than the sum of its proper divisors (32177071).

1200001211021 is an equidigital number, since it uses as much as digits as its factorization.

1200001211021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32177070.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 1200001211021 its reverse (1201121000021), we get a palindrome (2401122211042).

The spelling of 1200001211021 in words is "one trillion, two hundred billion, one million, two hundred eleven thousand, twenty-one".