211223220 has 48 divisors (see below), whose sum is σ = 636921600. Its totient is φ = 51993216.

The previous prime is 211223137. The next prime is 211223231. The reversal of 211223220 is 22322112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 211223220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 134620 + ... + 136179.

It is an arithmetic number, because the mean of its divisors is an integer number (13269200).

Almost surely, 2^211223220 is an apocalyptic number.

211223220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211223220 is an abundant number, since it is smaller than the sum of its proper divisors (425698380).

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

211223220 is a wasteful number, since it uses less digits than its factorization.

211223220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270824 (or 270822 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 211223220 is about 14533.5205645432. The cubic root of 211223220 is about 595.5440449177.

Adding to 211223220 its reverse (22322112), we get a palindrome (233545332).

It can be divided in two parts, 21122 and 3220, that added together give a palindrome (24342).

The spelling of 211223220 in words is "two hundred eleven million, two hundred twenty-three thousand, two hundred twenty".