212858381 has 2 divisors, whose sum is σ = 212858382. Its totient is φ = 212858380.

The previous prime is 212858351. The next prime is 212858483. The reversal of 212858381 is 183858212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 204061225 + 8797156 = 14285^2 + 2966^2 .

It is a cyclic number.

It is not a de Polignac number, because 212858381 - 2¹⁴ = 212841997 is a prime.

It is a super-2 number, since 2×212858381² = 90617380723882322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212858351) 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 as a sum of consecutive naturals, namely, 106429190 + 106429191.

It is an arithmetic number, because the mean of its divisors is an integer number (106429191).

Almost surely, 2^212858381 is an apocalyptic number.

It is an amenable number.

212858381 is a deficient number, since it is larger than the sum of its proper divisors (1).

212858381 is an equidigital number, since it uses as much as digits as its factorization.

212858381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30720, while the sum is 38.

The square root of 212858381 is about 14589.6669256018. Note that the first 3 decimals coincide. The cubic root of 212858381 is about 597.0768755512.

The spelling of 212858381 in words is "two hundred twelve million, eight hundred fifty-eight thousand, three hundred eighty-one".