211820117 has 8 divisors (see below), whose sum is σ = 223306752. Its totient is φ = 200624400.

The previous prime is 211820111. The next prime is 211820143. The reversal of 211820117 is 711028112.

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 211820117 - 2⁴ = 211820101 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211820092 and 211820101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211820111) 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, 71234 + ... + 74147.

It is an arithmetic number, because the mean of its divisors is an integer number (27913344).

Almost surely, 2^211820117 is an apocalyptic number.

It is an amenable number.

211820117 is a deficient number, since it is larger than the sum of its proper divisors (11486635).

211820117 is a wasteful number, since it uses less digits than its factorization.

211820117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145459.

The product of its (nonzero) digits is 224, while the sum is 23.

The square root of 211820117 is about 14554.0412600762. The cubic root of 211820117 is about 596.1045011796.

Adding to 211820117 its reverse (711028112), we get a palindrome (922848229).

The spelling of 211820117 in words is "two hundred eleven million, eight hundred twenty thousand, one hundred seventeen".