212128369 has 4 divisors (see below), whose sum is σ = 223293040. Its totient is φ = 200963700.

The previous prime is 212128361. The next prime is 212128373. The reversal of 212128369 is 963821212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 212128369 - 2³ = 212128361 is a prime.

It is a super-2 number, since 2×212128369² = 89996889869200322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212128361) 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, 5582307 + ... + 5582344.

It is an arithmetic number, because the mean of its divisors is an integer number (55823260).

Almost surely, 2^212128369 is an apocalyptic number.

It is an amenable number.

212128369 is a deficient number, since it is larger than the sum of its proper divisors (11164671).

212128369 is a wasteful number, since it uses less digits than its factorization.

212128369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11164670.

The product of its digits is 10368, while the sum is 34.

The square root of 212128369 is about 14564.6273210131. The cubic root of 212128369 is about 596.3935221105.

The spelling of 212128369 in words is "two hundred twelve million, one hundred twenty-eight thousand, three hundred sixty-nine".