205405215 has 16 divisors (see below), whose sum is σ = 331904736. Its totient is φ = 108464000.

The previous prime is 205405177. The next prime is 205405217. The reversal of 205405215 is 512504502.

It is a happy number.

It is not a de Polignac number, because 205405215 - 2¹⁷ = 205274143 is a prime.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205405217) 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, 66276 + ... + 69305.

It is an arithmetic number, because the mean of its divisors is an integer number (20744046).

Almost surely, 2^205405215 is an apocalyptic number.

205405215 is a deficient number, since it is larger than the sum of its proper divisors (126499521).

205405215 is a wasteful number, since it uses less digits than its factorization.

205405215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135690.

The product of its (nonzero) digits is 2000, while the sum is 24.

The square root of 205405215 is about 14331.9647990078. The cubic root of 205405215 is about 590.0251018718.

Adding to 205405215 its reverse (512504502), we get a palindrome (717909717).

The spelling of 205405215 in words is "two hundred five million, four hundred five thousand, two hundred fifteen".