213121021109 has 4 divisors (see below), whose sum is σ = 213132852300. Its totient is φ = 213109189920.

The previous prime is 213121021097. The next prime is 213121021111. The reversal of 213121021109 is 901120121312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 120554784100 + 92566237009 = 347210^2 + 304247^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213121021109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213121021129) 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, 5888534 + ... + 5924615.

It is an arithmetic number, because the mean of its divisors is an integer number (53283213075).

Almost surely, 2^213121021109 is an apocalyptic number.

It is an amenable number.

213121021109 is a deficient number, since it is larger than the sum of its proper divisors (11831191).

213121021109 is a wasteful number, since it uses less digits than its factorization.

213121021109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11831190.

The product of its (nonzero) digits is 216, while the sum is 23.

The spelling of 213121021109 in words is "two hundred thirteen billion, one hundred twenty-one million, twenty-one thousand, one hundred nine".