210745 has 8 divisors (see below), whose sum is σ = 255816. Its totient is φ = 166656.

The previous prime is 210739. The next prime is 210761. The reversal of 210745 is 547012.

It can be written as a sum of positive squares in 4 ways, for example, as 64 + 210681 = 8^2 + 459^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 210745 - 2⁵ = 210713 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

210745 is a lucky number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 379 + ... + 751.

It is an arithmetic number, because the mean of its divisors is an integer number (31977).

2²¹⁰⁷⁴⁵ is an apocalyptic number.

It is an amenable number.

210745 is a deficient number, since it is larger than the sum of its proper divisors (45071).

210745 is a wasteful number, since it uses less digits than its factorization.

210745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491.

The product of its (nonzero) digits is 280, while the sum is 19.

The square root of 210745 is about 459.0697114818. The cubic root of 210745 is about 59.5094258070.

Adding to 210745 its reverse (547012), we get a palindrome (757757).

The spelling of 210745 in words is "two hundred ten thousand, seven hundred forty-five".