1213031121 has 4 divisors (see below), whose sum is σ = 1617374832. Its totient is φ = 808687412.

The previous prime is 1213031101. The next prime is 1213031137. The reversal of 1213031121 is 1211303121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1213031121 - 2¹³ = 1213022929 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1213031121.

It is not an unprimeable number, because it can be changed into a prime (1213031101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 202171851 + ... + 202171856.

It is an arithmetic number, because the mean of its divisors is an integer number (404343708).

Almost surely, 2^1213031121 is an apocalyptic number.

It is an amenable number.

1213031121 is a deficient number, since it is larger than the sum of its proper divisors (404343711).

1213031121 is an equidigital number, since it uses as much as digits as its factorization.

1213031121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404343710.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 1213031121 is about 34828.5963110775. The cubic root of 1213031121 is about 1066.4912935096.

Adding to 1213031121 its reverse (1211303121), we get a palindrome (2424334242).

Subtracting from 1213031121 its reverse (1211303121), we obtain a cube (1728000 = 120³).

The spelling of 1213031121 in words is "one billion, two hundred thirteen million, thirty-one thousand, one hundred twenty-one".