212313521 has 6 divisors (see below), whose sum is σ = 246977010. Its totient is φ = 181982976.

The previous prime is 212313487. The next prime is 212313533. The reversal of 212313521 is 125313212.

It can be written as a sum of positive squares in only one way, i.e., 196000000 + 16313521 = 14000^2 + 4039^2 .

It is a de Polignac number, because none of the positive numbers 2^k-212313521 is a prime.

It is a nialpdrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 212313493 and 212313502.

It is not an unprimeable number, because it can be changed into a prime (212319521) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2166416 + ... + 2166513.

It is an arithmetic number, because the mean of its divisors is an integer number (41162835).

Almost surely, 2^212313521 is an apocalyptic number.

It is an amenable number.

212313521 is a deficient number, since it is larger than the sum of its proper divisors (34663489).

212313521 is an equidigital number, since it uses as much as digits as its factorization.

212313521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4332943 (or 4332936 counting only the distinct ones).

The product of its digits is 360, while the sum is 20.

The square root of 212313521 is about 14570.9821563270. The cubic root of 212313521 is about 596.5669883667.

Adding to 212313521 its reverse (125313212), we get a palindrome (337626733).

The spelling of 212313521 in words is "two hundred twelve million, three hundred thirteen thousand, five hundred twenty-one".