65660221 has 8 divisors (see below), whose sum is σ = 72493344. Its totient is φ = 58971120.

The previous prime is 65660207. The next prime is 65660251. The reversal of 65660221 is 12206656.

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

It is a cyclic number.

It is not a de Polignac number, because 65660221 - 2⁹ = 65659709 is a prime.

It is a super-2 number, since 2×65660221² = 8622529243537682, 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 65660221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65660251) 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, 35046 + ... + 36871.

It is an arithmetic number, because the mean of its divisors is an integer number (9061668).

Almost surely, 2^65660221 is an apocalyptic number.

It is an amenable number.

65660221 is a deficient number, since it is larger than the sum of its proper divisors (6833123).

65660221 is a wasteful number, since it uses less digits than its factorization.

65660221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72011.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 65660221 is about 8103.0994687218. The cubic root of 65660221 is about 403.4293093247.

Adding to 65660221 its reverse (12206656), we get a palindrome (77866877).

The spelling of 65660221 in words is "sixty-five million, six hundred sixty thousand, two hundred twenty-one".