212820997 has 2 divisors, whose sum is σ = 212820998. Its totient is φ = 212820996.

The previous prime is 212820991. The next prime is 212821013. The reversal of 212820997 is 799028212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 196868961 + 15952036 = 14031^2 + 3994^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212820997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212820991) 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 as a sum of consecutive naturals, namely, 106410498 + 106410499.

It is an arithmetic number, because the mean of its divisors is an integer number (106410499).

Almost surely, 2^212820997 is an apocalyptic number.

It is an amenable number.

212820997 is a deficient number, since it is larger than the sum of its proper divisors (1).

212820997 is an equidigital number, since it uses as much as digits as its factorization.

212820997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 212820997 is about 14588.3856886223. The cubic root of 212820997 is about 597.0419189310.

The spelling of 212820997 in words is "two hundred twelve million, eight hundred twenty thousand, nine hundred ninety-seven".