205820172 has 18 divisors (see below), whose sum is σ = 520267748. Its totient is φ = 68606712.

The previous prime is 205820099. The next prime is 205820177. The reversal of 205820172 is 271028502.

It is a tau number, because it is divible by the number of its divisors (18).

It is not an unprimeable number, because it can be changed into a prime (205820177) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2858578 + ... + 2858649.

Almost surely, 2^205820172 is an apocalyptic number.

It is an amenable number.

205820172 is an abundant number, since it is smaller than the sum of its proper divisors (314447576).

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

205820172 is a wasteful number, since it uses less digits than its factorization.

205820172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5717237 (or 5717232 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 205820172 is about 14346.4341214115. The cubic root of 205820172 is about 590.4221550172.

Adding to 205820172 its reverse (271028502), we get a palindrome (476848674).

The spelling of 205820172 in words is "two hundred five million, eight hundred twenty thousand, one hundred seventy-two".