212120209997 has 2 divisors, whose sum is σ = 212120209998. Its totient is φ = 212120209996.

The previous prime is 212120209993. The next prime is 212120210009. The reversal of 212120209997 is 799902021212.

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., 209058358441 + 3061851556 = 457229^2 + 55334^2 .

It is a cyclic number.

It is not a de Polignac number, because 212120209997 - 2² = 212120209993 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212120209993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106060104998 + 106060104999.

It is an arithmetic number, because the mean of its divisors is an integer number (106060104999).

Almost surely, 2^212120209997 is an apocalyptic number.

It is an amenable number.

212120209997 is a deficient number, since it is larger than the sum of its proper divisors (1).

212120209997 is an equidigital number, since it uses as much as digits as its factorization.

212120209997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81648, while the sum is 44.

The spelling of 212120209997 in words is "two hundred twelve billion, one hundred twenty million, two hundred nine thousand, nine hundred ninety-seven".