1211020100109 has 24 divisors (see below), whose sum is σ = 1852505174520. Its totient is φ = 759709375488.

The previous prime is 1211020100107. The next prime is 1211020100153. The reversal of 1211020100109 is 9010010201121.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 539034956100 + 671985144009 = 734190^2 + 819747^2 .

It is not a de Polignac number, because 1211020100109 - 2¹ = 1211020100107 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1211020100091 and 1211020100100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211020100107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 37219 + ... + 1556735.

It is an arithmetic number, because the mean of its divisors is an integer number (77187715605).

Almost surely, 2^{1211020100109} is an apocalyptic number.

It is an amenable number.

1211020100109 is a deficient number, since it is larger than the sum of its proper divisors (641485074411).

1211020100109 is a wasteful number, since it uses less digits than its factorization.

1211020100109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1524749 (or 1524746 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 18.

The spelling of 1211020100109 in words is "one trillion, two hundred eleven billion, twenty million, one hundred thousand, one hundred nine".