665243100 has 108 divisors (see below), whose sum is σ = 2090022480. Its totient is φ = 176985600.

The previous prime is 665243083. The next prime is 665243129. The reversal of 665243100 is 1342566.

665243100 is a `hidden beast` number, since 6 + 652 + 4 + 3 + 1 + 0 + 0 = 666.

It is a super-2 number, since 2×665243100² = 885096764195220000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 754660 + ... + 755540.

It is an arithmetic number, because the mean of its divisors is an integer number (19352060).

Almost surely, 2^665243100 is an apocalyptic number.

665243100 is a gapful number since it is divisible by the number (60) 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 665243100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1045011240).

665243100 is an abundant number, since it is smaller than the sum of its proper divisors (1424779380).

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

665243100 is a wasteful number, since it uses less digits than its factorization.

665243100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1740 (or 1730 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 665243100 is about 25792.3069925899. The cubic root of 665243100 is about 872.9582216085.

Adding to 665243100 its reverse (1342566), we get a palindrome (666585666).

The spelling of 665243100 in words is "six hundred sixty-five million, two hundred forty-three thousand, one hundred".