211940820 has 384 divisors, whose sum is σ = 858009600. Its totient is φ = 42177024.

The previous prime is 211940789. The next prime is 211940843. The reversal of 211940820 is 28049112.

It is a super-2 number, since 2×211940820² = 89837822364544800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 933547 + ... + 933773.

It is an arithmetic number, because the mean of its divisors is an integer number (2234400).

Almost surely, 2^211940820 is an apocalyptic number.

211940820 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 211940820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (429004800).

211940820 is an abundant number, since it is smaller than the sum of its proper divisors (646068780).

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

211940820 is a wasteful number, since it uses less digits than its factorization.

211940820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284 (or 276 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 211940820 is about 14558.1873871715. The cubic root of 211940820 is about 596.2177072024.

Adding to 211940820 its reverse (28049112), we get a palindrome (239989932).

The spelling of 211940820 in words is "two hundred eleven million, nine hundred forty thousand, eight hundred twenty".