212404240 has 20 divisors (see below), whose sum is σ = 493840044. Its totient is φ = 84961664.

The previous prime is 212404237. The next prime is 212404243. The reversal of 212404240 is 42404212.

212404240 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 (212404237) and next prime (212404243).

It can be written as a sum of positive squares in 2 ways, for example, as 52533504 + 159870736 = 7248^2 + 12644^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×212404240² = 90231122339955200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (212404243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1327447 + ... + 1327606.

Almost surely, 2^212404240 is an apocalyptic number.

212404240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

212404240 is an abundant number, since it is smaller than the sum of its proper divisors (281435804).

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

212404240 is a wasteful number, since it uses less digits than its factorization.

212404240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2655066 (or 2655060 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 19.

The square root of 212404240 is about 14574.0948260947. The cubic root of 212404240 is about 596.6519448875.

Adding to 212404240 its reverse (42404212), we get a palindrome (254808452).

The spelling of 212404240 in words is "two hundred twelve million, four hundred four thousand, two hundred forty".