205143540 has 192 divisors, whose sum is σ = 692127744. Its totient is φ = 44416512.

The previous prime is 205143529. The next prime is 205143553. The reversal of 205143540 is 45341502.

205143540 = T₄₉₁ + T₄₉₂ + ... + T₁₁₀₄.

It is a self number, because there is not a number n which added to its sum of digits gives 205143540.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 668067 + ... + 668373.

It is an arithmetic number, because the mean of its divisors is an integer number (3604832).

Almost surely, 2^205143540 is an apocalyptic number.

205143540 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 205143540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (346063872).

205143540 is an abundant number, since it is smaller than the sum of its proper divisors (486984204).

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

205143540 is a wasteful number, since it uses less digits than its factorization.

205143540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406 (or 404 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 205143540 is about 14322.8328203606. The cubic root of 205143540 is about 589.7744421721.

The spelling of 205143540 in words is "two hundred five million, one hundred forty-three thousand, five hundred forty".