1213021121 has 8 divisors (see below), whose sum is σ = 1338192744. Its totient is φ = 1092401280.

The previous prime is 1213021091. The next prime is 1213021157. The reversal of 1213021121 is 1211203121.

It can be written as a sum of positive squares in 4 ways, for example, as 119793025 + 1093228096 = 10945^2 + 33064^2 .

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 1213021121 - 2³⁰ = 139279297 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1213021096 and 1213021105.

It is not an unprimeable number, because it can be changed into a prime (1213021321) 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, 1137386 + ... + 1138451.

It is an arithmetic number, because the mean of its divisors is an integer number (167274093).

Almost surely, 2^1213021121 is an apocalyptic number.

It is an amenable number.

1213021121 is a deficient number, since it is larger than the sum of its proper divisors (125171623).

1213021121 is a wasteful number, since it uses less digits than its factorization.

1213021121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2275891.

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

The square root of 1213021121 is about 34828.4527505888. The cubic root of 1213021121 is about 1066.4883628505.

Adding to 1213021121 its reverse (1211203121), we get a palindrome (2424224242).

The spelling of 1213021121 in words is "one billion, two hundred thirteen million, twenty-one thousand, one hundred twenty-one".