1011001211221 has 8 divisors (see below), whose sum is σ = 1015466108184. Its totient is φ = 1006540431360.

The previous prime is 1011001211153. The next prime is 1011001211263. The reversal of 1011001211221 is 1221121001101.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 949192290225 + 61808920996 = 974265^2 + 248614^2 .

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 1011001211221 - 2⁷ = 1011001211093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1011001211291) 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, 536550 + ... + 1519831.

It is an arithmetic number, because the mean of its divisors is an integer number (126933263523).

Almost surely, 2^{1011001211221} is an apocalyptic number.

It is an amenable number.

1011001211221 is a deficient number, since it is larger than the sum of its proper divisors (4464896963).

1011001211221 is a wasteful number, since it uses less digits than its factorization.

1011001211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2058551.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 1011001211221 its reverse (1221121001101), we get a palindrome (2232122212322).

The spelling of 1011001211221 in words is "one trillion, eleven billion, one million, two hundred eleven thousand, two hundred twenty-one".