211284840 has 256 divisors, whose sum is σ = 748984320. Its totient is φ = 47185920.

The previous prime is 211284839. The next prime is 211284851. The reversal of 211284840 is 48482112.

It is a super-2 number, since 2×211284840² = 89282567227651200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 211284798 and 211284807.

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, 821992 + ... + 822248.

It is an arithmetic number, because the mean of its divisors is an integer number (2925720).

Almost surely, 2^211284840 is an apocalyptic number.

211284840 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 211284840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (374492160).

211284840 is an abundant number, since it is smaller than the sum of its proper divisors (537699480).

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

211284840 is a wasteful number, since it uses less digits than its factorization.

211284840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332 (or 328 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 30.

The square root of 211284840 is about 14535.6403367722. The cubic root of 211284840 is about 595.6019518342.

The spelling of 211284840 in words is "two hundred eleven million, two hundred eighty-four thousand, eight hundred forty".