64563421217 has 4 divisors (see below), whose sum is σ = 66646112256. Its totient is φ = 62480730180.

The previous prime is 64563421213. The next prime is 64563421229. The reversal of 64563421217 is 71212436546.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 71212436546 = 2 ⋅35606218273.

It is a cyclic number.

It is not a de Polignac number, because 64563421217 - 2² = 64563421213 is a prime.

It is a super-2 number, since 2×64563421217² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64563421213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1041345473 + ... + 1041345534.

It is an arithmetic number, because the mean of its divisors is an integer number (16661528064).

Almost surely, 2^64563421217 is an apocalyptic number.

It is an amenable number.

64563421217 is a deficient number, since it is larger than the sum of its proper divisors (2082691039).

64563421217 is a wasteful number, since it uses less digits than its factorization.

64563421217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2082691038.

The product of its digits is 241920, while the sum is 41.

The spelling of 64563421217 in words is "sixty-four billion, five hundred sixty-three million, four hundred twenty-one thousand, two hundred seventeen".