1261031121 has 81 divisors (see below), whose sum is σ = 2261673531. Its totient is φ = 674993088.

The previous prime is 1261031089. The next prime is 1261031129. The reversal of 1261031121 is 1211301621.

1261031121 = 1³ + 2³ + ... + 266³.

The square root of 1261031121 is 35511.

It is a perfect power (a square), and thus also a powerful number.

1261031121 is a `hidden beast` number, since 1 + 2 + 610 + 31 + 1 + 21 = 666.

1261031121 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 242144721 + 1018886400 = 15561^2 + 31920^2 .

It is not a de Polignac number, because 1261031121 - 2⁵ = 1261031089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1261031094 and 1261031103.

It is not an unprimeable number, because it can be changed into a prime (1261031129) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 14168845 + ... + 14168933.

Almost surely, 2^1261031121 is an apocalyptic number.

1261031121 is the 35511-st square number.

1261031121 is the 17756-th centered octagonal number.

It is an amenable number.

1261031121 is a deficient number, since it is larger than the sum of its proper divisors (1000642410).

1261031121 is an equidigital number, since it uses as much as digits as its factorization.

1261031121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The cubic root of 1261031121 is about 1080.3768463717.

Adding to 1261031121 its reverse (1211301621), we get a palindrome (2472332742).

The spelling of 1261031121 in words is "one billion, two hundred sixty-one million, thirty-one thousand, one hundred twenty-one".