205173020 has 96 divisors (see below), whose sum is σ = 500834880. Its totient is φ = 69949440.

The previous prime is 205173011. The next prime is 205173037. The reversal of 205173020 is 20371502.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 205172983 and 205173001.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 202034 + ... + 203046.

It is an arithmetic number, because the mean of its divisors is an integer number (5217030).

Almost surely, 2^205173020 is an apocalyptic number.

205173020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 205173020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (250417440).

205173020 is an abundant number, since it is smaller than the sum of its proper divisors (295661860).

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

205173020 is a wasteful number, since it uses less digits than its factorization.

205173020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1095 (or 1093 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 205173020 is about 14323.8619094154. The cubic root of 205173020 is about 589.8026918517.

The spelling of 205173020 in words is "two hundred five million, one hundred seventy-three thousand, twenty".