205138920 has 128 divisors (see below), whose sum is σ = 710461440. Its totient is φ = 46414080.

The previous prime is 205138907. The next prime is 205138937. The reversal of 205138920 is 29831502.

It is a happy number.

205138920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 85335 + ... + 87705.

It is an arithmetic number, because the mean of its divisors is an integer number (5550480).

Almost surely, 2^205138920 is an apocalyptic number.

205138920 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 205138920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (355230720).

205138920 is an abundant number, since it is smaller than the sum of its proper divisors (505322520).

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

205138920 is a wasteful number, since it uses less digits than its factorization.

205138920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2495 (or 2491 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 205138920 is about 14322.6715385084. The cubic root of 205138920 is about 589.7700147383.

The spelling of 205138920 in words is "two hundred five million, one hundred thirty-eight thousand, nine hundred twenty".