210120021201991 has 2 divisors, whose sum is σ = 210120021201992. Its totient is φ = 210120021201990.

The previous prime is 210120021201983. The next prime is 210120021202051. The reversal of 210120021201991 is 199102120021012.

210120021201991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 210120021201991 - 2³ = 210120021201983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (210120021201691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105060010600995 + 105060010600996.

It is an arithmetic number, because the mean of its divisors is an integer number (105060010600996).

Almost surely, 2^{210120021201991} is an apocalyptic number.

210120021201991 is a deficient number, since it is larger than the sum of its proper divisors (1).

210120021201991 is an equidigital number, since it uses as much as digits as its factorization.

210120021201991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 31.

The spelling of 210120021201991 in words is "two hundred ten trillion, one hundred twenty billion, twenty-one million, two hundred one thousand, nine hundred ninety-one".