1221021111211 has 8 divisors (see below), whose sum is σ = 1374991515648. Its totient is φ = 1074212121000.

The previous prime is 1221021111197. The next prime is 1221021111241. The reversal of 1221021111211 is 1121111201221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221021111211 - 2⁷ = 1221021111083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221021111241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1790353195 + ... + 1790353876.

It is an arithmetic number, because the mean of its divisors is an integer number (171873939456).

Almost surely, 2^{1221021111211} is an apocalyptic number.

1221021111211 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1221021111211 is a deficient number, since it is larger than the sum of its proper divisors (153970404437).

1221021111211 is a wasteful number, since it uses less digits than its factorization.

1221021111211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3580707113.

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

Adding to 1221021111211 its reverse (1121111201221), we get a palindrome (2342132312432).

The spelling of 1221021111211 in words is "one trillion, two hundred twenty-one billion, twenty-one million, one hundred eleven thousand, two hundred eleven".