212281638 has 8 divisors (see below), whose sum is σ = 424563288. Its totient is φ = 70760544.

The previous prime is 212281631. The next prime is 212281639. The reversal of 212281638 is 836182212.

212281638 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

212281638 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 212281599 and 212281608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212281631) 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 3 ways as a sum of consecutive naturals, for example, 17690131 + ... + 17690142.

It is an arithmetic number, because the mean of its divisors is an integer number (53070411).

Almost surely, 2^212281638 is an apocalyptic number.

212281638 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

212281638 is a wasteful number, since it uses less digits than its factorization.

212281638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35380278.

The product of its digits is 9216, while the sum is 33.

The square root of 212281638 is about 14569.8880572227. Note that the first 3 decimals coincide. The cubic root of 212281638 is about 596.5371248306.

The spelling of 212281638 in words is "two hundred twelve million, two hundred eighty-one thousand, six hundred thirty-eight".