213665605 has 16 divisors (see below), whose sum is σ = 272288304. Its totient is φ = 160399360.

The previous prime is 213665603. The next prime is 213665623. The reversal of 213665605 is 506566312.

213665605 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 17189316 + 196476289 = 4146^2 + 14017^2 .

It is not a de Polignac number, because 213665605 - 2¹ = 213665603 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213665603) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26445 + ... + 33565.

It is an arithmetic number, because the mean of its divisors is an integer number (17018019).

Almost surely, 2^213665605 is an apocalyptic number.

It is an amenable number.

213665605 is a deficient number, since it is larger than the sum of its proper divisors (58622699).

213665605 is a wasteful number, since it uses less digits than its factorization.

213665605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7496.

The product of its (nonzero) digits is 32400, while the sum is 34.

The square root of 213665605 is about 14617.3049841618. The cubic root of 213665605 is about 597.8306894199.

The spelling of 213665605 in words is "two hundred thirteen million, six hundred sixty-five thousand, six hundred five".