1221002011 has 2 divisors, whose sum is σ = 1221002012. Its totient is φ = 1221002010.

The previous prime is 1221002009. The next prime is 1221002021. The reversal of 1221002011 is 1102001221.

It is an a-pointer prime, because the next prime (1221002021) can be obtained adding 1221002011 to its sum of digits (10).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221002011 - 2¹ = 1221002009 is a prime.

Together with 1221002009, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1221002021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610501005 + 610501006.

It is an arithmetic number, because the mean of its divisors is an integer number (610501006).

Almost surely, 2^1221002011 is an apocalyptic number.

1221002011 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221002011 is an equidigital number, since it uses as much as digits as its factorization.

1221002011 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1221002011 is about 34942.8391948908. The cubic root of 1221002011 is about 1068.8221852182.

Adding to 1221002011 its reverse (1102001221), we get a palindrome (2323003232).

The spelling of 1221002011 in words is "one billion, two hundred twenty-one million, two thousand, eleven".