211521311109 has 12 divisors (see below), whose sum is σ = 305535222252. Its totient is φ = 141012158400.

The previous prime is 211521311101. The next prime is 211521311117. The reversal of 211521311109 is 901113125112.

It is a happy number.

211521311109 is a `hidden beast` number, since 2 + 1 + 1 + 521 + 31 + 1 + 109 = 666.

211521311109 is digitally balanced in base 2, 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 (211521311101) and next prime (211521311117).

It can be written as a sum of positive squares in 2 ways, for example, as 55108971009 + 156412340100 = 234753^2 + 395490^2 .

It is not a de Polignac number, because 211521311109 - 2³ = 211521311101 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211521311101) 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 11 ways as a sum of consecutive naturals, for example, 737079 + ... + 983019.

It is an arithmetic number, because the mean of its divisors is an integer number (25461268521).

Almost surely, 2^211521311109 is an apocalyptic number.

It is an amenable number.

211521311109 is a deficient number, since it is larger than the sum of its proper divisors (94013911143).

211521311109 is a wasteful number, since it uses less digits than its factorization.

211521311109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 341508 (or 341505 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 27.

The spelling of 211521311109 in words is "two hundred eleven billion, five hundred twenty-one million, three hundred eleven thousand, one hundred nine".