205091000 has 128 divisors (see below), whose sum is σ = 516447360. Its totient is φ = 76032000.

The previous prime is 205090999. The next prime is 205091017. The reversal of 205091000 is 190502.

205091000 = 71³ + 72³ + ... + 170³.

It is a self number, because there is not a number n which added to its sum of digits gives 205091000.

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, 850880 + ... + 851120.

It is an arithmetic number, because the mean of its divisors is an integer number (4034745).

Almost surely, 2^205091000 is an apocalyptic number.

205091000 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 205091000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (258223680).

205091000 is an abundant number, since it is smaller than the sum of its proper divisors (311356360).

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

205091000 is a wasteful number, since it uses less digits than its factorization.

205091000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322 (or 308 counting only the distinct ones).

The product of its (nonzero) digits is 90, while the sum is 17.

The square root of 205091000 is about 14320.9985685356. The cubic root of 205091000 is about 589.7240881697.

The spelling of 205091000 in words is "two hundred five million, ninety-one thousand".