1221000212011 has 4 divisors (see below), whose sum is σ = 1292823753912. Its totient is φ = 1149176670112.

The previous prime is 1221000212009. The next prime is 1221000212021. The reversal of 1221000212011 is 1102120001221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221000212011 - 2¹ = 1221000212009 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221000211982 and 1221000212000.

It is not an unprimeable number, because it can be changed into a prime (1221000212021) 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, 35911770925 + ... + 35911770958.

It is an arithmetic number, because the mean of its divisors is an integer number (323205938478).

Almost surely, 2^{1221000212011} is an apocalyptic number.

1221000212011 is a deficient number, since it is larger than the sum of its proper divisors (71823541901).

1221000212011 is an equidigital number, since it uses as much as digits as its factorization.

1221000212011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71823541900.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1221000212011 its reverse (1102120001221), we get a palindrome (2323120213232).

The spelling of 1221000212011 in words is "one trillion, two hundred twenty-one billion, two hundred twelve thousand, eleven".