1211413121 has 4 divisors (see below), whose sum is σ = 1212263472. Its totient is φ = 1210562772.

The previous prime is 1211413117. The next prime is 1211413123. The reversal of 1211413121 is 1213141121.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1213141121 = 3823 ⋅317327.

It is a cyclic number.

It is not a de Polignac number, because 1211413121 - 2² = 1211413117 is a prime.

It is a super-3 number, since 3×1211413121³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1211413121.

It is not an unprimeable number, because it can be changed into a prime (1211413123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 423035 + ... + 425888.

It is an arithmetic number, because the mean of its divisors is an integer number (303065868).

Almost surely, 2^1211413121 is an apocalyptic number.

It is an amenable number.

1211413121 is a deficient number, since it is larger than the sum of its proper divisors (850351).

1211413121 is an equidigital number, since it uses as much as digits as its factorization.

1211413121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 850350.

The product of its digits is 48, while the sum is 17.

The square root of 1211413121 is about 34805.3605210462. The cubic root of 1211413121 is about 1066.0169031789.

Adding to 1211413121 its reverse (1213141121), we get a palindrome (2424554242).

Subtracting 1211413121 from its reverse (1213141121), we obtain a cube (1728000 = 120³).

The spelling of 1211413121 in words is "one billion, two hundred eleven million, four hundred thirteen thousand, one hundred twenty-one".