206661540 has 96 divisors (see below), whose sum is σ = 607178880. Its totient is φ = 52448256.

The previous prime is 206661529. The next prime is 206661541. The reversal of 206661540 is 45166602.

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 = 206661498 and 206661507.

It is not an unprimeable number, because it can be changed into a prime (206661541) by changing a digit.

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, 126207 + ... + 127833.

It is an arithmetic number, because the mean of its divisors is an integer number (6324780).

Almost surely, 2^206661540 is an apocalyptic number.

206661540 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 206661540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (303589440).

206661540 is an abundant number, since it is smaller than the sum of its proper divisors (400517340).

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

206661540 is a wasteful number, since it uses less digits than its factorization.

206661540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1741 (or 1739 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 206661540 is about 14375.7274598540. The cubic root of 206661540 is about 591.2255860489.

The spelling of 206661540 in words is "two hundred six million, six hundred sixty-one thousand, five hundred forty".