212857217 has 2 divisors, whose sum is σ = 212857218. Its totient is φ = 212857216.

The previous prime is 212857213. The next prime is 212857231. The reversal of 212857217 is 712758212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166126321 + 46730896 = 12889^2 + 6836^2 .

It is a cyclic number.

It is not a de Polignac number, because 212857217 - 2² = 212857213 is a prime.

It is not a weakly prime, because it can be changed into another prime (212857213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106428608 + 106428609.

It is an arithmetic number, because the mean of its divisors is an integer number (106428609).

Almost surely, 2^212857217 is an apocalyptic number.

It is an amenable number.

212857217 is a deficient number, since it is larger than the sum of its proper divisors (1).

212857217 is an equidigital number, since it uses as much as digits as its factorization.

212857217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15680, while the sum is 35.

The square root of 212857217 is about 14589.6270343008. The cubic root of 212857217 is about 597.0757871926.

The spelling of 212857217 in words is "two hundred twelve million, eight hundred fifty-seven thousand, two hundred seventeen".