665620206 has 8 divisors (see below), whose sum is σ = 1331240424. Its totient is φ = 221873400.

The previous prime is 665620201. The next prime is 665620211. The reversal of 665620206 is 602026566.

It is an interprime number because it is at equal distance from previous prime (665620201) and next prime (665620211).

It is a sphenic number, since it is the product of 3 distinct primes.

665620206 is an admirable number.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665620201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55468345 + ... + 55468356.

It is an arithmetic number, because the mean of its divisors is an integer number (166405053).

Almost surely, 2^665620206 is an apocalyptic number.

665620206 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

665620206 is a wasteful number, since it uses less digits than its factorization.

665620206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110936706.

The product of its (nonzero) digits is 25920, while the sum is 33.

The square root of 665620206 is about 25799.6163924970. The cubic root of 665620206 is about 873.1231415697.

It can be divided in two parts, 6656 and 20206, that added together give a palindrome (26862).

The spelling of 665620206 in words is "six hundred sixty-five million, six hundred twenty thousand, two hundred six".