1211022101 has 4 divisors (see below), whose sum is σ = 1212007104. Its totient is φ = 1210037100.

The previous prime is 1211022097. The next prime is 1211022157. The reversal of 1211022101 is 1012201121.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1012201121 = 61 ⋅16593461.

It is a cyclic number.

It is not a de Polignac number, because 1211022101 - 2² = 1211022097 is a prime.

It is a super-2 number, since 2×1211022101² = 2933149058220908402, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211022181) 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, 490655 + ... + 493116.

It is an arithmetic number, because the mean of its divisors is an integer number (303001776).

Almost surely, 2^1211022101 is an apocalyptic number.

It is an amenable number.

1211022101 is a deficient number, since it is larger than the sum of its proper divisors (985003).

1211022101 is an equidigital number, since it uses as much as digits as its factorization.

1211022101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 985002.

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

The square root of 1211022101 is about 34799.7428295095. The cubic root of 1211022101 is about 1065.9021945028.

Adding to 1211022101 its reverse (1012201121), we get a palindrome (2223223222).

The spelling of 1211022101 in words is "one billion, two hundred eleven million, twenty-two thousand, one hundred one".