64444442521 has 2 divisors, whose sum is σ = 64444442522. Its totient is φ = 64444442520.

The previous prime is 64444442519. The next prime is 64444442539. The reversal of 64444442521 is 12524444446.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46671553296 + 17772889225 = 216036^2 + 133315^2 .

It is a cyclic number.

It is not a de Polignac number, because 64444442521 - 2¹ = 64444442519 is a prime.

It is a super-4 number, since 4×64444442521⁴ (a number of 44 digits) contains 4444 as substring.

Together with 64444442519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (64444442501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32222221260 + 32222221261.

It is an arithmetic number, because the mean of its divisors is an integer number (32222221261).

Almost surely, 2^64444442521 is an apocalyptic number.

It is an amenable number.

64444442521 is a deficient number, since it is larger than the sum of its proper divisors (1).

64444442521 is an equidigital number, since it uses as much as digits as its factorization.

64444442521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 491520, while the sum is 40.

Adding to 64444442521 its reverse (12524444446), we get a palindrome (76968886967).

It can be divided in two parts, 644444425 and 21, that added together give a palindrome (644444446).

The spelling of 64444442521 in words is "sixty-four billion, four hundred forty-four million, four hundred forty-two thousand, five hundred twenty-one".