64985881 has 2 divisors, whose sum is σ = 64985882. Its totient is φ = 64985880.

The previous prime is 64985873. The next prime is 64985887. The reversal of 64985881 is 18858946.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62552281 + 2433600 = 7909^2 + 1560^2 .

It is a cyclic number.

It is not a de Polignac number, because 64985881 - 2³ = 64985873 is a prime.

It is a super-3 number, since 3×64985881³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (64985887) 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, 32492940 + 32492941.

It is an arithmetic number, because the mean of its divisors is an integer number (32492941).

Almost surely, 2^64985881 is an apocalyptic number.

It is an amenable number.

64985881 is a deficient number, since it is larger than the sum of its proper divisors (1).

64985881 is an equidigital number, since it uses as much as digits as its factorization.

64985881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 552960, while the sum is 49.

The square root of 64985881 is about 8061.3820775348. The cubic root of 64985881 is about 402.0434616344.

The spelling of 64985881 in words is "sixty-four million, nine hundred eighty-five thousand, eight hundred eighty-one".