211211800 has 48 divisors (see below), whose sum is σ = 495883440. Its totient is φ = 83656320.

The previous prime is 211211789. The next prime is 211211801. The reversal of 211211800 is 8112112.

It is a super-2 number, since 2×211211800² = 89220848918480000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211211801) 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 11 ways as a sum of consecutive naturals, for example, 15474 + ... + 25726.

It is an arithmetic number, because the mean of its divisors is an integer number (10330905).

Almost surely, 2^211211800 is an apocalyptic number.

211211800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211211800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (247941720).

211211800 is an abundant number, since it is smaller than the sum of its proper divisors (284671640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

211211800 is a wasteful number, since it uses less digits than its factorization.

211211800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10372 (or 10363 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

The square root of 211211800 is about 14533.1276743859. The cubic root of 211211800 is about 595.5333118244.

Adding to 211211800 its reverse (8112112), we get a palindrome (219323912).

The spelling of 211211800 in words is "two hundred eleven million, two hundred eleven thousand, eight hundred".