65511350221 has 8 divisors (see below), whose sum is σ = 68384912024. Its totient is φ = 62695840320.

The previous prime is 65511350189. The next prime is 65511350227. The reversal of 65511350221 is 12205311556.

It can be written as a sum of positive squares in 4 ways, for example, as 26958027721 + 38553322500 = 164189^2 + 196350^2 .

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 65511350221 - 2⁵ = 65511350189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65511350227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14510670 + ... + 14515183.

It is an arithmetic number, because the mean of its divisors is an integer number (8548114003).

Almost surely, 2^65511350221 is an apocalyptic number.

65511350221 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

65511350221 is a deficient number, since it is larger than the sum of its proper divisors (2873561803).

65511350221 is a wasteful number, since it uses less digits than its factorization.

65511350221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29025951.

The product of its (nonzero) digits is 9000, while the sum is 31.

Adding to 65511350221 its reverse (12205311556), we get a palindrome (77716661777).

The spelling of 65511350221 in words is "sixty-five billion, five hundred eleven million, three hundred fifty thousand, two hundred twenty-one".