205645420 has 12 divisors (see below), whose sum is σ = 431855424. Its totient is φ = 82258160.

The previous prime is 205645411. The next prime is 205645439. The reversal of 205645420 is 24546502.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5141116 + ... + 5141155.

It is an arithmetic number, because the mean of its divisors is an integer number (35987952).

Almost surely, 2^205645420 is an apocalyptic number.

205645420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205645420 is an abundant number, since it is smaller than the sum of its proper divisors (226210004).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

205645420 is a wasteful number, since it uses less digits than its factorization.

205645420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10282280 (or 10282278 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 28.

The square root of 205645420 is about 14340.3423947966. The cubic root of 205645420 is about 590.2550080264.

The spelling of 205645420 in words is "two hundred five million, six hundred forty-five thousand, four hundred twenty".