212210381 has 4 divisors (see below), whose sum is σ = 213091164. Its totient is φ = 211329600.

The previous prime is 212210377. The next prime is 212210413. The reversal of 212210381 is 183012212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 162154756 + 50055625 = 12734^2 + 7075^2 .

It is a cyclic number.

It is not a de Polignac number, because 212210381 - 2² = 212210377 is a prime.

It is a super-2 number, since 2×212210381² = 90066491608330322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212240381) 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, 440030 + ... + 440511.

It is an arithmetic number, because the mean of its divisors is an integer number (53272791).

Almost surely, 2^212210381 is an apocalyptic number.

It is an amenable number.

212210381 is a deficient number, since it is larger than the sum of its proper divisors (880783).

212210381 is an equidigital number, since it uses as much as digits as its factorization.

212210381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 880782.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 212210381 is about 14567.4425003156. The cubic root of 212210381 is about 596.4703704262.

Adding to 212210381 its reverse (183012212), we get a palindrome (395222593).

The spelling of 212210381 in words is "two hundred twelve million, two hundred ten thousand, three hundred eighty-one".