1221011001111 has 64 divisors (see below), whose sum is σ = 1849520977920. Its totient is φ = 710087226240.

The previous prime is 1221011001107. The next prime is 1221011001121. The reversal of 1221011001111 is 1111001101221.

It is not a de Polignac number, because 1221011001111 - 2² = 1221011001107 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221011001121) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 21053125 + ... + 21111041.

It is an arithmetic number, because the mean of its divisors is an integer number (28898765280).

Almost surely, 2^{1221011001111} is an apocalyptic number.

1221011001111 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1221011001111 is a deficient number, since it is larger than the sum of its proper divisors (628509976809).

1221011001111 is a wasteful number, since it uses less digits than its factorization.

1221011001111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58236.

The product of its (nonzero) digits is 4, while the sum is 12.

Adding to 1221011001111 its reverse (1111001101221), we get a palindrome (2332012102332).

The spelling of 1221011001111 in words is "one trillion, two hundred twenty-one billion, eleven million, one thousand, one hundred eleven".