212020221997 has 2 divisors, whose sum is σ = 212020221998. Its totient is φ = 212020221996.

The previous prime is 212020221979. The next prime is 212020222033. The reversal of 212020221997 is 799122020212.

Together with previous prime (212020221979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 138677291236 + 73342930761 = 372394^2 + 270819^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212020221997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212020221397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106010110998 + 106010110999.

It is an arithmetic number, because the mean of its divisors is an integer number (106010110999).

Almost surely, 2^212020221997 is an apocalyptic number.

It is an amenable number.

212020221997 is a deficient number, since it is larger than the sum of its proper divisors (1).

212020221997 is an equidigital number, since it uses as much as digits as its factorization.

212020221997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 37.

The spelling of 212020221997 in words is "two hundred twelve billion, twenty million, two hundred twenty-one thousand, nine hundred ninety-seven".