211423140 has 72 divisors (see below), whose sum is σ = 647981880. Its totient is φ = 55793664.

The previous prime is 211423109. The next prime is 211423141. The reversal of 211423140 is 41324112.

It can be written as a sum of positive squares in 4 ways, for example, as 79816356 + 131606784 = 8934^2 + 11472^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (211423141) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 11406 + ... + 23514.

Almost surely, 2^211423140 is an apocalyptic number.

211423140 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 211423140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (323990940).

211423140 is an abundant number, since it is smaller than the sum of its proper divisors (436558740).

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

211423140 is a wasteful number, since it uses less digits than its factorization.

211423140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12221 (or 12216 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 211423140 is about 14540.3968308984. The cubic root of 211423140 is about 595.7318772055.

Adding to 211423140 its reverse (41324112), we get a palindrome (252747252).

The spelling of 211423140 in words is "two hundred eleven million, four hundred twenty-three thousand, one hundred forty".