1011011001221 has 16 divisors (see below), whose sum is σ = 1094107014000. Its totient is φ = 928683959808.

The previous prime is 1011011001211. The next prime is 1011011001227. The reversal of 1011011001221 is 1221001101101.

It can be written as a sum of positive squares in 8 ways, for example, as 2364390625 + 1008646610596 = 48625^2 + 1004314^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1011011001221 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1011011001227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2828255 + ... + 3165603.

It is an arithmetic number, because the mean of its divisors is an integer number (68381688375).

Almost surely, 2^{1011011001221} is an apocalyptic number.

It is an amenable number.

1011011001221 is a deficient number, since it is larger than the sum of its proper divisors (83096012779).

1011011001221 is a wasteful number, since it uses less digits than its factorization.

1011011001221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338488.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 1011011001221 its reverse (1221001101101), we get a palindrome (2232012102322).

The spelling of 1011011001221 in words is "one trillion, eleven billion, eleven million, one thousand, two hundred twenty-one".