1605206500 has 24 divisors (see below), whose sum is σ = 3505772088. Its totient is φ = 642082400.

The previous prime is 1605206479. The next prime is 1605206503. The reversal of 1605206500 is 56025061.

It can be written as a sum of positive squares in 4 ways, for example, as 3125824 + 1602080676 = 1768^2 + 40026^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (1605206503) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1604707 + ... + 1605706.

It is an arithmetic number, because the mean of its divisors is an integer number (146073837).

Almost surely, 2^1605206500 is an apocalyptic number.

1605206500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1605206500 is an abundant number, since it is smaller than the sum of its proper divisors (1900565588).

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

1605206500 is a wasteful number, since it uses less digits than its factorization.

1605206500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3210432 (or 3210420 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 1605206500 is about 40065.0283913540. The cubic root of 1605206500 is about 1170.8743798660.

The spelling of 1605206500 in words is "one billion, six hundred five million, two hundred six thousand, five hundred".