211431220 has 192 divisors, whose sum is σ = 609638400. Its totient is φ = 59466240.

The previous prime is 211431197. The next prime is 211431247. The reversal of 211431220 is 22134112.

211431220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 211431194 and 211431203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1181091 + ... + 1181269.

It is an arithmetic number, because the mean of its divisors is an integer number (3175200).

Almost surely, 2^211431220 is an apocalyptic number.

211431220 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 211431220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (304819200).

211431220 is an abundant number, since it is smaller than the sum of its proper divisors (398207180).

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

211431220 is a wasteful number, since it uses less digits than its factorization.

211431220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278 (or 276 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 211431220 is about 14540.6746748560. The cubic root of 211431220 is about 595.7394661765.

Adding to 211431220 its reverse (22134112), we get a palindrome (233565332).

The spelling of 211431220 in words is "two hundred eleven million, four hundred thirty-one thousand, two hundred twenty".