1221021122211 has 48 divisors (see below), whose sum is σ = 1966081927680. Its totient is φ = 723858068160.

The previous prime is 1221021122207. The next prime is 1221021122213. The reversal of 1221021122211 is 1122211201221.

1221021122211 is a `hidden beast` number, since 1 + 221 + 0 + 211 + 22 + 211 = 666.

It is not a de Polignac number, because 1221021122211 - 2² = 1221021122207 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221021122213) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8250876 + ... + 8397558.

It is an arithmetic number, because the mean of its divisors is an integer number (40960040160).

Almost surely, 2^{1221021122211} is an apocalyptic number.

1221021122211 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1221021122211 is a deficient number, since it is larger than the sum of its proper divisors (745060805469).

1221021122211 is a wasteful number, since it uses less digits than its factorization.

1221021122211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148536 (or 148533 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 1221021122211 its reverse (1122211201221), we get a palindrome (2343232323432).

The spelling of 1221021122211 in words is "one trillion, two hundred twenty-one billion, twenty-one million, one hundred twenty-two thousand, two hundred eleven".