1221100221121 has 8 divisors (see below), whose sum is σ = 1332120950784. Its totient is φ = 1110081427920.

The previous prime is 1221100221119. The next prime is 1221100221127. The reversal of 1221100221121 is 1211220011221.

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 1221100221121 - 2¹ = 1221100221119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221100221095 and 1221100221104.

It is not an unprimeable number, because it can be changed into a prime (1221100221127) 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, 1044160 + ... + 1879486.

It is an arithmetic number, because the mean of its divisors is an integer number (166515118848).

Almost surely, 2^{1221100221121} is an apocalyptic number.

1221100221121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221100221121 is a deficient number, since it is larger than the sum of its proper divisors (111020729663).

1221100221121 is a wasteful number, since it uses less digits than its factorization.

1221100221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 968231.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1221100221121 its reverse (1211220011221), we get a palindrome (2432320232342).

The spelling of 1221100221121 in words is "one trillion, two hundred twenty-one billion, one hundred million, two hundred twenty-one thousand, one hundred twenty-one".