205172220 has 48 divisors (see below), whose sum is σ = 626709888. Its totient is φ = 49738560.

The previous prime is 205172207. The next prime is 205172239. The reversal of 205172220 is 22271502.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 154774 + ... + 156093.

It is an arithmetic number, because the mean of its divisors is an integer number (13056456).

Almost surely, 2^205172220 is an apocalyptic number.

205172220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205172220 is an abundant number, since it is smaller than the sum of its proper divisors (421537668).

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

205172220 is a wasteful number, since it uses less digits than its factorization.

205172220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310890 (or 310888 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 205172220 is about 14323.8339839583. The cubic root of 205172220 is about 589.8019252746.

The spelling of 205172220 in words is "two hundred five million, one hundred seventy-two thousand, two hundred twenty".