212040305 has 4 divisors (see below), whose sum is σ = 254448372. Its totient is φ = 169632240.

The previous prime is 212040281. The next prime is 212040313. The reversal of 212040305 is 503040212.

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 153165376 + 58874929 = 12376^2 + 7673^2 .

It is not a de Polignac number, because 212040305 - 2¹⁰ = 212039281 is a prime.

It is a super-2 number, since 2×212040305² = 89922181888986050, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21204026 + ... + 21204035.

It is an arithmetic number, because the mean of its divisors is an integer number (63612093).

Almost surely, 2^212040305 is an apocalyptic number.

It is an amenable number.

212040305 is a deficient number, since it is larger than the sum of its proper divisors (42408067).

212040305 is an equidigital number, since it uses as much as digits as its factorization.

212040305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42408066.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 212040305 is about 14561.6037921652. The cubic root of 212040305 is about 596.3109807874.

Adding to 212040305 its reverse (503040212), we get a palindrome (715080517).

The spelling of 212040305 in words is "two hundred twelve million, forty thousand, three hundred five".