215640205 has 16 divisors (see below), whose sum is σ = 283046400. Its totient is φ = 156410560.

The previous prime is 215640169. The next prime is 215640209. The reversal of 215640205 is 502046512.

215640205 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 215640205 - 2¹³ = 215632013 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 215640205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215640209) 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, 16356 + ... + 26434.

It is an arithmetic number, because the mean of its divisors is an integer number (17690400).

Almost surely, 2^215640205 is an apocalyptic number.

It is an amenable number.

215640205 is a deficient number, since it is larger than the sum of its proper divisors (67406195).

215640205 is a wasteful number, since it uses less digits than its factorization.

215640205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10484.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 215640205 is about 14684.6928806836. The cubic root of 215640205 is about 599.6666713358. Note that the first 4 decimals are identical.

Adding to 215640205 its reverse (502046512), we get a palindrome (717686717).

The spelling of 215640205 in words is "two hundred fifteen million, six hundred forty thousand, two hundred five".