212212440 has 128 divisors (see below), whose sum is σ = 771724800. Its totient is φ = 51442560.

The previous prime is 212212423. The next prime is 212212457. The reversal of 212212440 is 44212212.

212212440 is a `hidden beast` number, since 2 + 1 + 221 + 2 + 440 = 666.

212212440 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (212212423) and next prime (212212457).

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

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 31 ways as a sum of consecutive naturals, for example, 2949 + ... + 20811.

It is an arithmetic number, because the mean of its divisors is an integer number (6029100).

Almost surely, 2^212212440 is an apocalyptic number.

212212440 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 212212440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (385862400).

212212440 is an abundant number, since it is smaller than the sum of its proper divisors (559512360).

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

212212440 is a wasteful number, since it uses less digits than its factorization.

212212440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17894 (or 17884 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 212212440 is about 14567.5131714373. The cubic root of 212212440 is about 596.4722995315.

Adding to 212212440 its reverse (44212212), we get a palindrome (256424652).

The spelling of 212212440 in words is "two hundred twelve million, two hundred twelve thousand, four hundred forty".