65660660 has 24 divisors (see below), whose sum is σ = 148494696. Its totient is φ = 24243840.

The previous prime is 65660659. The next prime is 65660663. The reversal of 65660660 is 6606656.

It can be written as a sum of positive squares in 4 ways, for example, as 2521744 + 63138916 = 1588^2 + 7946^2 .

It is a super-2 number, since 2×65660660² = 8622644543271200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 65660660.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65660663) 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, 126011 + ... + 126530.

It is an arithmetic number, because the mean of its divisors is an integer number (6187279).

Almost surely, 2^65660660 is an apocalyptic number.

It is an amenable number.

65660660 is an abundant number, since it is smaller than the sum of its proper divisors (82834036).

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

65660660 is a wasteful number, since it uses less digits than its factorization.

65660660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252563 (or 252561 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 35.

The square root of 65660660 is about 8103.1265570766. The cubic root of 65660660 is about 403.4302084234.

It can be divided in two parts, 656 and 60660, that added together give a palindrome (61316).

The spelling of 65660660 in words is "sixty-five million, six hundred sixty thousand, six hundred sixty".