64999943 has 2 divisors, whose sum is σ = 64999944.
Its totient is φ = 64999942.
The previous prime is 64999939. The next prime is 64999981. The reversal of 64999943 is 34999946.
It is a weak prime.
It is a cyclic number.
It is not a de Polignac number, because 64999943 - 22 = 64999939 is a prime.
It is a Chen prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (64999903) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32499971 + 32499972.
It is an arithmetic number, because the mean of its divisors is an integer number (32499972).
Almost surely, 264999943 is an apocalyptic number.
64999943 is a deficient number, since it is larger than the sum of its proper divisors (1).
64999943 is an equidigital number, since it uses as much as digits as its factorization.
64999943 is an evil number, because the sum of its binary digits is even.
The product of its digits is 1889568, while the sum is 53.
The square root of 64999943 is about 8062.2542133078.
The cubic root of 64999943 is about 402.0724583300.
The spelling of 64999943 in words is "sixty-four million, nine hundred ninety-nine thousand, nine hundred forty-three".