1211020211 has 4 divisors (see below), whose sum is σ = 1282256712. Its totient is φ = 1139783712.

The previous prime is 1211020207. The next prime is 1211020229. The reversal of 1211020211 is 1120201121.

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

It is a cyclic number.

It is not a de Polignac number, because 1211020211 - 2² = 1211020207 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211020192 and 1211020201.

It is not an unprimeable number, because it can be changed into a prime (1211023211) 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, 35618225 + ... + 35618258.

It is an arithmetic number, because the mean of its divisors is an integer number (320564178).

Almost surely, 2^1211020211 is an apocalyptic number.

1211020211 is a deficient number, since it is larger than the sum of its proper divisors (71236501).

1211020211 is an equidigital number, since it uses as much as digits as its factorization.

1211020211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71236500.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 1211020211 is about 34799.7156741258. The cubic root of 1211020211 is about 1065.9016399970.

Adding to 1211020211 its reverse (1120201121), we get a palindrome (2331221332).

The spelling of 1211020211 in words is "one billion, two hundred eleven million, twenty thousand, two hundred eleven".