65217121719 has 4 divisors (see below), whose sum is σ = 86956162296. Its totient is φ = 43478081144.

The previous prime is 65217121679. The next prime is 65217121747. The reversal of 65217121719 is 91712171256.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 65217121719 - 2⁷ = 65217121591 is a prime.

It is a super-2 number, since 2×65217121719² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65217121219) 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, 10869520284 + ... + 10869520289.

It is an arithmetic number, because the mean of its divisors is an integer number (21739040574).

Almost surely, 2^65217121719 is an apocalyptic number.

65217121719 is a deficient number, since it is larger than the sum of its proper divisors (21739040577).

65217121719 is a wasteful number, since it uses less digits than its factorization.

65217121719 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21739040576.

The product of its digits is 52920, while the sum is 42.

The spelling of 65217121719 in words is "sixty-five billion, two hundred seventeen million, one hundred twenty-one thousand, seven hundred nineteen".