65215622111721 has 16 divisors (see below), whose sum is σ = 87351428161536. Its totient is φ = 43278481487376.

The previous prime is 65215622111719. The next prime is 65215622111743. The reversal of 65215622111721 is 12711122651256.

It is a happy number.

It is not a de Polignac number, because 65215622111721 - 2¹ = 65215622111719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (65215622111711) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3888496 + ... + 12064478.

It is an arithmetic number, because the mean of its divisors is an integer number (5459464260096).

Almost surely, 2^{65215622111721} is an apocalyptic number.

It is an amenable number.

65215622111721 is a deficient number, since it is larger than the sum of its proper divisors (22135806049815).

65215622111721 is a wasteful number, since it uses less digits than its factorization.

65215622111721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8188132.

The product of its digits is 100800, while the sum is 42.

Adding to 65215622111721 its reverse (12711122651256), we get a palindrome (77926744762977).

The spelling of 65215622111721 in words is "sixty-five trillion, two hundred fifteen billion, six hundred twenty-two million, one hundred eleven thousand, seven hundred twenty-one".