210120109 has 4 divisors (see below), whose sum is σ = 217365660. Its totient is φ = 202874560.

The previous prime is 210120101. The next prime is 210120133. The reversal of 210120109 is 901021012.

210120109 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 146168100 + 63952009 = 12090^2 + 7997^2 .

It is a cyclic number.

It is not a de Polignac number, because 210120109 - 2³ = 210120101 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 210120092 and 210120101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210120101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3622732 + ... + 3622789.

It is an arithmetic number, because the mean of its divisors is an integer number (54341415).

Almost surely, 2^210120109 is an apocalyptic number.

210120109 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

210120109 is a deficient number, since it is larger than the sum of its proper divisors (7245551).

210120109 is an equidigital number, since it uses as much as digits as its factorization.

210120109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7245550.

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 210120109 is about 14495.5203080124. The cubic root of 210120109 is about 594.5054940790.

The spelling of 210120109 in words is "two hundred ten million, one hundred twenty thousand, one hundred nine".