64399548221 has 2 divisors, whose sum is σ = 64399548222. Its totient is φ = 64399548220.

The previous prime is 64399548163. The next prime is 64399548287. The reversal of 64399548221 is 12284599346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52493683225 + 11905864996 = 229115^2 + 109114^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64399548221 is a prime.

It is a super-2 number, since 2×64399548221² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64399547221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32199774110 + 32199774111.

It is an arithmetic number, because the mean of its divisors is an integer number (32199774111).

Almost surely, 2^64399548221 is an apocalyptic number.

It is an amenable number.

64399548221 is a deficient number, since it is larger than the sum of its proper divisors (1).

64399548221 is an equidigital number, since it uses as much as digits as its factorization.

64399548221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3732480, while the sum is 53.

The spelling of 64399548221 in words is "sixty-four billion, three hundred ninety-nine million, five hundred forty-eight thousand, two hundred twenty-one".