212121111001 has 8 divisors (see below), whose sum is σ = 219440853000. Its totient is φ = 204801717120.

The previous prime is 212121110959. The next prime is 212121111049. The reversal of 212121111001 is 100111121212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 72200227401 + 139920883600 = 268701^2 + 374060^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 212121111001 - 2²¹ = 212119013849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212121151001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2006925 + ... + 2109973.

It is an arithmetic number, because the mean of its divisors is an integer number (27430106625).

Almost surely, 2^212121111001 is an apocalyptic number.

It is an amenable number.

212121111001 is a deficient number, since it is larger than the sum of its proper divisors (7319741999).

212121111001 is a wasteful number, since it uses less digits than its factorization.

212121111001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174059.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 212121111001 its reverse (100111121212), we get a palindrome (312232232213).

The spelling of 212121111001 in words is "two hundred twelve billion, one hundred twenty-one million, one hundred eleven thousand, one".