213020645 has 4 divisors (see below), whose sum is σ = 255624780. Its totient is φ = 170416512.

The previous prime is 213020627. The next prime is 213020651. The reversal of 213020645 is 546020312.

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 39150049 + 173870596 = 6257^2 + 13186^2 .

It is a cyclic number.

It is not a de Polignac number, because 213020645 - 2¹⁶ = 212955109 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 213020645.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21302060 + ... + 21302069.

It is an arithmetic number, because the mean of its divisors is an integer number (63906195).

Almost surely, 2^213020645 is an apocalyptic number.

It is an amenable number.

213020645 is a deficient number, since it is larger than the sum of its proper divisors (42604135).

213020645 is an equidigital number, since it uses as much as digits as its factorization.

213020645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42604134.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 213020645 is about 14595.2267882346. The cubic root of 213020645 is about 597.2285561718.

Adding to 213020645 its reverse (546020312), we get a palindrome (759040957).

The spelling of 213020645 in words is "two hundred thirteen million, twenty thousand, six hundred forty-five".