211230820 has 24 divisors (see below), whose sum is σ = 448572600. Its totient is φ = 83542272.

The previous prime is 211230793. The next prime is 211230839. The reversal of 211230820 is 28032112.

It can be written as a sum of positive squares in 4 ways, for example, as 9193024 + 202037796 = 3032^2 + 14214^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57555 + ... + 61114.

It is an arithmetic number, because the mean of its divisors is an integer number (18690525).

Almost surely, 2^211230820 is an apocalyptic number.

211230820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211230820 is an abundant number, since it is smaller than the sum of its proper divisors (237341780).

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

211230820 is a wasteful number, since it uses less digits than its factorization.

211230820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118767 (or 118765 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 211230820 is about 14533.7820267128. The cubic root of 211230820 is about 595.5511875675.

Adding to 211230820 its reverse (28032112), we get a palindrome (239262932).

The spelling of 211230820 in words is "two hundred eleven million, two hundred thirty thousand, eight hundred twenty".