1211002101 has 6 divisors (see below), whose sum is σ = 1749225270. Its totient is φ = 807334728.

The previous prime is 1211002043. The next prime is 1211002159. The reversal of 1211002101 is 1012001121.

It is a happy number.

1211002101 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (1211002043) and next prime (1211002159).

It can be written as a sum of positive squares in only one way, i.e., 1080699876 + 130302225 = 32874^2 + 11415^2 .

It is not a de Polignac number, because 1211002101 - 2⁷ = 1211001973 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 134555789 = 1211002101 / (1 + 2 + 1 + 1 + 0 + 0 + 2 + 1 + 0 + 1).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211002181) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 67277886 + ... + 67277903.

It is an arithmetic number, because the mean of its divisors is an integer number (291537545).

Almost surely, 2^1211002101 is an apocalyptic number.

It is an amenable number.

1211002101 is a deficient number, since it is larger than the sum of its proper divisors (538223169).

1211002101 is a wasteful number, since it uses less digits than its factorization.

1211002101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134555795 (or 134555792 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 1211002101 is about 34799.4554698777. The cubic root of 1211002101 is about 1065.8963266877.

Adding to 1211002101 its reverse (1012001121), we get a palindrome (2223003222).

It can be divided in two parts, 121100 and 2101, that added together give a square (123201 = 351²).

The spelling of 1211002101 in words is "one billion, two hundred eleven million, two thousand, one hundred one".