212857745 has 4 divisors (see below), whose sum is σ = 255429300. Its totient is φ = 170286192.

The previous prime is 212857739. The next prime is 212857747. The reversal of 212857745 is 547758212.

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 146337409 + 66520336 = 12097^2 + 8156^2 .

It is a cyclic number.

It is not a de Polignac number, because 212857745 - 2²⁴ = 196080529 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (212857747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21285770 + ... + 21285779.

It is an arithmetic number, because the mean of its divisors is an integer number (63857325).

Almost surely, 2^212857745 is an apocalyptic number.

It is an amenable number.

212857745 is a deficient number, since it is larger than the sum of its proper divisors (42571555).

212857745 is an equidigital number, since it uses as much as digits as its factorization.

212857745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42571554.

The product of its digits is 156800, while the sum is 41.

The square root of 212857745 is about 14589.6451293375. The cubic root of 212857745 is about 597.0762808815.

The spelling of 212857745 in words is "two hundred twelve million, eight hundred fifty-seven thousand, seven hundred forty-five".