1211212011 has 4 divisors (see below), whose sum is σ = 1614949352. Its totient is φ = 807474672.

The previous prime is 1211211979. The next prime is 1211212063. The reversal of 1211212011 is 1102121121.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1211212011 - 2⁵ = 1211211979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211212511) 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, 201868666 + ... + 201868671.

It is an arithmetic number, because the mean of its divisors is an integer number (403737338).

Almost surely, 2^1211212011 is an apocalyptic number.

1211212011 is a deficient number, since it is larger than the sum of its proper divisors (403737341).

1211212011 is an equidigital number, since it uses as much as digits as its factorization.

1211212011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 403737340.

The product of its (nonzero) digits is 8, while the sum is 12.

The square root of 1211212011 is about 34802.4713346624. The cubic root of 1211212011 is about 1065.9579091219.

Adding to 1211212011 its reverse (1102121121), we get a palindrome (2313333132).

The spelling of 1211212011 in words is "one billion, two hundred eleven million, two hundred twelve thousand, eleven".