211221010001 has 4 divisors (see below), whose sum is σ = 211231400100. Its totient is φ = 211210619904.

The previous prime is 211221009953. The next prime is 211221010003. The reversal of 211221010001 is 100010122112.

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 76385904400 + 134835105601 = 276380^2 + 367199^2 .

It is a cyclic number.

It is not a de Polignac number, because 211221010001 - 2¹⁴ = 211220993617 is a prime.

It is a super-2 number, since 2×211221010001² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (211221010003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5164496 + ... + 5205233.

It is an arithmetic number, because the mean of its divisors is an integer number (52807850025).

Almost surely, 2^211221010001 is an apocalyptic number.

It is an amenable number.

211221010001 is a deficient number, since it is larger than the sum of its proper divisors (10390099).

211221010001 is a wasteful number, since it uses less digits than its factorization.

211221010001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10390098.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 211221010001 its reverse (100010122112), we get a palindrome (311231132113).

The spelling of 211221010001 in words is "two hundred eleven billion, two hundred twenty-one million, ten thousand, one".