210109985 has 4 divisors (see below), whose sum is σ = 252131988. Its totient is φ = 168087984.

The previous prime is 210109973. The next prime is 210109993. The reversal of 210109985 is 589901012.

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 58721569 + 151388416 = 7663^2 + 12304^2 .

It is a cyclic number.

It is not a de Polignac number, because 210109985 - 2⁴ = 210109969 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21010994 + ... + 21011003.

It is an arithmetic number, because the mean of its divisors is an integer number (63032997).

Almost surely, 2^210109985 is an apocalyptic number.

It is an amenable number.

210109985 is a deficient number, since it is larger than the sum of its proper divisors (42022003).

210109985 is an equidigital number, since it uses as much as digits as its factorization.

210109985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42022002.

The product of its (nonzero) digits is 6480, while the sum is 35.

The square root of 210109985 is about 14495.1710924708. The cubic root of 210109985 is about 594.4959457778.

The spelling of 210109985 in words is "two hundred ten million, one hundred nine thousand, nine hundred eighty-five".