212731345 has 4 divisors (see below), whose sum is σ = 255277620. Its totient is φ = 170185072.

The previous prime is 212731333. The next prime is 212731349. The reversal of 212731345 is 543137212.

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 92236816 + 120494529 = 9604^2 + 10977^2 .

It is a cyclic number.

It is not a de Polignac number, because 212731345 - 2⁵ = 212731313 is a prime.

It is not an unprimeable number, because it can be changed into a prime (212731349) 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, 21273130 + ... + 21273139.

It is an arithmetic number, because the mean of its divisors is an integer number (63819405).

Almost surely, 2^212731345 is an apocalyptic number.

It is an amenable number.

212731345 is a deficient number, since it is larger than the sum of its proper divisors (42546275).

212731345 is an equidigital number, since it uses as much as digits as its factorization.

212731345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42546274.

The product of its digits is 5040, while the sum is 28.

The square root of 212731345 is about 14585.3126466319. The cubic root of 212731345 is about 596.9580714399.

Adding to 212731345 its reverse (543137212), we get a palindrome (755868557).

The spelling of 212731345 in words is "two hundred twelve million, seven hundred thirty-one thousand, three hundred forty-five".