1211021220011 has 4 divisors (see below), whose sum is σ = 1221738222072. Its totient is φ = 1200304217952.

The previous prime is 1211021219999. The next prime is 1211021220023. The reversal of 1211021220011 is 1100221201121.

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

It is an interprime number because it is at equal distance from previous prime (1211021219999) and next prime (1211021220023).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211021220011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211021223011) 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, 5358500861 + ... + 5358501086.

It is an arithmetic number, because the mean of its divisors is an integer number (305434555518).

Almost surely, 2^{1211021220011} is an apocalyptic number.

1211021220011 is a deficient number, since it is larger than the sum of its proper divisors (10717002061).

1211021220011 is a wasteful number, since it uses less digits than its factorization.

1211021220011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10717002060.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1211021220011 its reverse (1100221201121), we get a palindrome (2311242421132).

The spelling of 1211021220011 in words is "one trillion, two hundred eleven billion, twenty-one million, two hundred twenty thousand, eleven".