210120221977 has 2 divisors, whose sum is σ = 210120221978. Its totient is φ = 210120221976.

The previous prime is 210120221953. The next prime is 210120222017. The reversal of 210120221977 is 779122021012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 162154403856 + 47965818121 = 402684^2 + 219011^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-210120221977 is a prime.

It is not a weakly prime, because it can be changed into another prime (210120221177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105060110988 + 105060110989.

It is an arithmetic number, because the mean of its divisors is an integer number (105060110989).

Almost surely, 2^210120221977 is an apocalyptic number.

It is an amenable number.

210120221977 is a deficient number, since it is larger than the sum of its proper divisors (1).

210120221977 is an equidigital number, since it uses as much as digits as its factorization.

210120221977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7056, while the sum is 34.

Adding to 210120221977 its reverse (779122021012), we get a palindrome (989242242989).

The spelling of 210120221977 in words is "two hundred ten billion, one hundred twenty million, two hundred twenty-one thousand, nine hundred seventy-seven".