1211212101 has 8 divisors (see below), whose sum is σ = 1761763104. Its totient is φ = 734067920.

The previous prime is 1211212063. The next prime is 1211212117. The reversal of 1211212101 is 1012121121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1211212101 - 2⁷ = 1211211973 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211212151) 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 7 ways as a sum of consecutive naturals, for example, 18351666 + ... + 18351731.

It is an arithmetic number, because the mean of its divisors is an integer number (220220388).

Almost surely, 2^1211212101 is an apocalyptic number.

1211212101 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211212101 is a deficient number, since it is larger than the sum of its proper divisors (550551003).

1211212101 is a wasteful number, since it uses less digits than its factorization.

1211212101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36703411.

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

The square root of 1211212101 is about 34802.4726276740. The cubic root of 1211212101 is about 1065.9579355242.

Adding to 1211212101 its reverse (1012121121), we get a palindrome (2223333222).

It can be divided in two parts, 1211 and 212101, that added together give a palindrome (213312).

The spelling of 1211212101 in words is "one billion, two hundred eleven million, two hundred twelve thousand, one hundred one".