205191840 has 192 divisors, whose sum is σ = 745065216. Its totient is φ = 46497792.

The previous prime is 205191827. The next prime is 205191871. The reversal of 205191840 is 48191502.

It is a happy number.

205191840 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 a junction number, because it is equal to n+sod(n) for n = 205191798 and 205191807.

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, 581104 + ... + 581456.

It is an arithmetic number, because the mean of its divisors is an integer number (3880548).

Almost surely, 2^205191840 is an apocalyptic number.

205191840 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 205191840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (372532608).

205191840 is an abundant number, since it is smaller than the sum of its proper divisors (539873376).

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

205191840 is a wasteful number, since it uses less digits than its factorization.

205191840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 551 (or 543 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 30.

The square root of 205191840 is about 14324.5188400867. The cubic root of 205191840 is about 589.8207250012.

The spelling of 205191840 in words is "two hundred five million, one hundred ninety-one thousand, eight hundred forty".