211100021 has 8 divisors (see below), whose sum is σ = 235908288. Its totient is φ = 187228000.

The previous prime is 211100017. The next prime is 211100023. The reversal of 211100021 is 120001112.

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 211100021 - 2² = 211100017 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 211099981 and 211100008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211100023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 233585 + ... + 234486.

It is an arithmetic number, because the mean of its divisors is an integer number (29488536).

Almost surely, 2^211100021 is an apocalyptic number.

It is an amenable number.

211100021 is a deficient number, since it is larger than the sum of its proper divisors (24808267).

211100021 is a wasteful number, since it uses less digits than its factorization.

211100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468123.

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 211100021 is about 14529.2815032265. The cubic root of 211100021 is about 595.4282358379.

Adding to 211100021 its reverse (120001112), we get a palindrome (331101133).

The spelling of 211100021 in words is "two hundred eleven million, one hundred thousand, twenty-one".