212031521 has 16 divisors (see below), whose sum is σ = 231686784. Its totient is φ = 192875904.

The previous prime is 212031517. The next prime is 212031527. The reversal of 212031521 is 125130212.

It is a happy number.

It is not a de Polignac number, because 212031521 - 2² = 212031517 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 212031521.

It is not an unprimeable number, because it can be changed into a prime (212031527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 435140 + ... + 435626.

It is an arithmetic number, because the mean of its divisors is an integer number (14480424).

Almost surely, 2^212031521 is an apocalyptic number.

It is an amenable number.

212031521 is a deficient number, since it is larger than the sum of its proper divisors (19655263).

212031521 is a wasteful number, since it uses less digits than its factorization.

212031521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 920.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 212031521 is about 14561.3021739129. The cubic root of 212031521 is about 596.3027463970.

Adding to 212031521 its reverse (125130212), we get a palindrome (337161733).

The spelling of 212031521 in words is "two hundred twelve million, thirty-one thousand, five hundred twenty-one".