1211413129 has 4 divisors (see below), whose sum is σ = 1211493780. Its totient is φ = 1211332480.

The previous prime is 1211413123. The next prime is 1211413139. The reversal of 1211413129 is 9213141121.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 967210000 + 244203129 = 31100^2 + 15627^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211413129 - 2⁹ = 1211412617 is a prime.

It is a super-3 number, since 3×1211413129³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10384 + ... + 50305.

It is an arithmetic number, because the mean of its divisors is an integer number (302873445).

Almost surely, 2^1211413129 is an apocalyptic number.

It is an amenable number.

1211413129 is a deficient number, since it is larger than the sum of its proper divisors (80651).

1211413129 is an equidigital number, since it uses as much as digits as its factorization.

1211413129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80650.

The product of its digits is 432, while the sum is 25.

The square root of 1211413129 is about 34805.3606359710. The cubic root of 1211413129 is about 1066.0169055255.

The spelling of 1211413129 in words is "one billion, two hundred eleven million, four hundred thirteen thousand, one hundred twenty-nine".