1211111313 has 4 divisors (see below), whose sum is σ = 1614815088. Its totient is φ = 807407540.

The previous prime is 1211111303. The next prime is 1211111333. The reversal of 1211111313 is 3131111121.

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 1211111313 - 2⁶ = 1211111249 is a prime.

It is a super-2 number, since 2×1211111313² = 2933581224953167938, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1211111292 and 1211111301.

It is not an unprimeable number, because it can be changed into a prime (1211111303) 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, 201851883 + ... + 201851888.

It is an arithmetic number, because the mean of its divisors is an integer number (403703772).

Almost surely, 2^1211111313 is an apocalyptic number.

It is an amenable number.

1211111313 is a deficient number, since it is larger than the sum of its proper divisors (403703775).

1211111313 is an equidigital number, since it uses as much as digits as its factorization.

1211111313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 403703774.

The product of its digits is 18, while the sum is 15.

The square root of 1211111313 is about 34801.0245969856. The cubic root of 1211111313 is about 1065.9283676919.

Adding to 1211111313 its reverse (3131111121), we get a palindrome (4342222434).

The spelling of 1211111313 in words is "one billion, two hundred eleven million, one hundred eleven thousand, three hundred thirteen".