1221121013 has 12 divisors (see below), whose sum is σ = 1495251360. Its totient is φ = 991586232.

The previous prime is 1221121003. The next prime is 1221121021. The reversal of 1221121013 is 3101211221.

It is not a de Polignac number, because 1221121013 - 2⁶ = 1221120949 is a prime.

It is a super-2 number, since 2×1221121013² = 2982273056780292338, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221121003) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 654881 + ... + 656742.

It is an arithmetic number, because the mean of its divisors is an integer number (124604280).

Almost surely, 2^1221121013 is an apocalyptic number.

It is an amenable number.

1221121013 is a deficient number, since it is larger than the sum of its proper divisors (274130347).

1221121013 is a wasteful number, since it uses less digits than its factorization.

1221121013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1311656 (or 1311649 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 14.

The square root of 1221121013 is about 34944.5419629447. The cubic root of 1221121013 is about 1068.8569074776.

Adding to 1221121013 its reverse (3101211221), we get a palindrome (4322332234).

The spelling of 1221121013 in words is "one billion, two hundred twenty-one million, one hundred twenty-one thousand, thirteen".