1211012111 has 16 divisors (see below), whose sum is σ = 1253145600. Its totient is φ = 1169731008.

The previous prime is 1211012107. The next prime is 1211012113. The reversal of 1211012111 is 1112101121.

It is a cyclic number.

It is not a de Polignac number, because 1211012111 - 2² = 1211012107 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211012092 and 1211012101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211012113) 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 15 ways as a sum of consecutive naturals, for example, 2062760 + ... + 2063346.

It is an arithmetic number, because the mean of its divisors is an integer number (78321600).

Almost surely, 2^1211012111 is an apocalyptic number.

1211012111 is a deficient number, since it is larger than the sum of its proper divisors (42133489).

1211012111 is an equidigital number, since it uses as much as digits as its factorization.

1211012111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1198.

The product of its (nonzero) digits is 4, while the sum is 11.

The square root of 1211012111 is about 34799.5992936700. The cubic root of 1211012111 is about 1065.8992635372.

Adding to 1211012111 its reverse (1112101121), we get a palindrome (2323113232).

The spelling of 1211012111 in words is "one billion, two hundred eleven million, twelve thousand, one hundred eleven".