1221020220111 has 16 divisors (see below), whose sum is σ = 1698837940224. Its totient is φ = 778609123424.

The previous prime is 1221020220089. The next prime is 1221020220113. The reversal of 1221020220111 is 1110220201221.

It is a cyclic number.

It is not a de Polignac number, because 1221020220111 - 2¹⁰ = 1221020219087 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221020220113) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6318850 + ... + 6509216.

It is an arithmetic number, because the mean of its divisors is an integer number (106177371264).

Almost surely, 2^{1221020220111} is an apocalyptic number.

1221020220111 is a deficient number, since it is larger than the sum of its proper divisors (477817720113).

1221020220111 is a wasteful number, since it uses less digits than its factorization.

1221020220111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283350.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1221020220111 its reverse (1110220201221), we get a palindrome (2331240421332).

The spelling of 1221020220111 in words is "one trillion, two hundred twenty-one billion, twenty million, two hundred twenty thousand, one hundred eleven".