212231687 has 4 divisors (see below), whose sum is σ = 212914416. Its totient is φ = 211548960.

The previous prime is 212231671. The next prime is 212231693. The reversal of 212231687 is 786132212.

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

It is a cyclic number.

It is not a de Polignac number, because 212231687 - 2⁴ = 212231671 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212231087) 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, 340898 + ... + 341519.

It is an arithmetic number, because the mean of its divisors is an integer number (53228604).

Almost surely, 2^212231687 is an apocalyptic number.

212231687 is a deficient number, since it is larger than the sum of its proper divisors (682729).

212231687 is an equidigital number, since it uses as much as digits as its factorization.

212231687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 682728.

The product of its digits is 8064, while the sum is 32.

The square root of 212231687 is about 14568.1737702431. The cubic root of 212231687 is about 596.4903317060.

Adding to 212231687 its reverse (786132212), we get a palindrome (998363899).

The spelling of 212231687 in words is "two hundred twelve million, two hundred thirty-one thousand, six hundred eighty-seven".