212243640 has 256 divisors, whose sum is σ = 783820800. Its totient is φ = 44875776.

The previous prime is 212243627. The next prime is 212243651. The reversal of 212243640 is 46342212.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 212243640.

It is a congruent number.

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 63 ways as a sum of consecutive naturals, for example, 1270837 + ... + 1271003.

It is an arithmetic number, because the mean of its divisors is an integer number (3061800).

Almost surely, 2^212243640 is an apocalyptic number.

212243640 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 212243640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (391910400).

212243640 is an abundant number, since it is smaller than the sum of its proper divisors (571577160).

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

212243640 is a wasteful number, since it uses less digits than its factorization.

212243640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 294 (or 290 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 212243640 is about 14568.5840080634. The cubic root of 212243640 is about 596.5015297120.

Adding to 212243640 its reverse (46342212), we get a palindrome (258585852).

The spelling of 212243640 in words is "two hundred twelve million, two hundred forty-three thousand, six hundred forty".