64744021 has 2 divisors, whose sum is σ = 64744022. Its totient is φ = 64744020.

The previous prime is 64744019. The next prime is 64744033. The reversal of 64744021 is 12044746.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64400625 + 343396 = 8025^2 + 586^2 .

It is a cyclic number.

It is not a de Polignac number, because 64744021 - 2¹ = 64744019 is a prime.

Together with 64744019, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64744061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32372010 + 32372011.

It is an arithmetic number, because the mean of its divisors is an integer number (32372011).

Almost surely, 2^64744021 is an apocalyptic number.

It is an amenable number.

64744021 is a deficient number, since it is larger than the sum of its proper divisors (1).

64744021 is an equidigital number, since it uses as much as digits as its factorization.

64744021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5376, while the sum is 28.

The square root of 64744021 is about 8046.3669441556. The cubic root of 64744021 is about 401.5440756565.

Adding to 64744021 its reverse (12044746), we get a palindrome (76788767).

The spelling of 64744021 in words is "sixty-four million, seven hundred forty-four thousand, twenty-one".