211122820 has 12 divisors (see below), whose sum is σ = 443357964. Its totient is φ = 84449120.

The previous prime is 211122809. The next prime is 211122833. The reversal of 211122820 is 28221112.

It can be written as a sum of positive squares in 2 ways, for example, as 27899524 + 183223296 = 5282^2 + 13536^2 .

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 5278051 + ... + 5278090.

It is an arithmetic number, because the mean of its divisors is an integer number (36946497).

Almost surely, 2^211122820 is an apocalyptic number.

211122820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211122820 is an abundant number, since it is smaller than the sum of its proper divisors (232235144).

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

211122820 is a wasteful number, since it uses less digits than its factorization.

211122820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10556150 (or 10556148 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 211122820 is about 14530.0660700494. The cubic root of 211122820 is about 595.4496706687.

Adding to 211122820 its reverse (28221112), we get a palindrome (239343932).

It can be divided in two parts, 21112 and 2820, that added together give a palindrome (23932).

The spelling of 211122820 in words is "two hundred eleven million, one hundred twenty-two thousand, eight hundred twenty".