1001221221111 has 32 divisors (see below), whose sum is σ = 1375511709888. Its totient is φ = 647326817280.

The previous prime is 1001221221083. The next prime is 1001221221163. The reversal of 1001221221111 is 1111221221001.

It is a happy number.

It is not a de Polignac number, because 1001221221111 - 2⁶ = 1001221221047 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001221221191) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44692165 + ... + 44714561.

It is an arithmetic number, because the mean of its divisors is an integer number (42984740934).

Almost surely, 2^{1001221221111} is an apocalyptic number.

1001221221111 is a deficient number, since it is larger than the sum of its proper divisors (374290488777).

1001221221111 is a wasteful number, since it uses less digits than its factorization.

1001221221111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23731.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1001221221111 its reverse (1111221221001), we get a palindrome (2112442442112).

The spelling of 1001221221111 in words is "one trillion, one billion, two hundred twenty-one million, two hundred twenty-one thousand, one hundred eleven".