64399999 has 2 divisors, whose sum is σ = 64400000. Its totient is φ = 64399998.

The previous prime is 64399997. The next prime is 64400009. The reversal of 64399999 is 99999346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64399999 - 2¹ = 64399997 is a prime.

Together with 64399997, it forms a pair of twin primes.

64399999 is a modest number, since divided by 9999 gives 6439 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64399997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32199999 + 32200000.

It is an arithmetic number, because the mean of its divisors is an integer number (32200000).

Almost surely, 2^64399999 is an apocalyptic number.

64399999 is a deficient number, since it is larger than the sum of its proper divisors (1).

64399999 is an equidigital number, since it uses as much as digits as its factorization.

64399999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4251528, while the sum is 58.

The square root of 64399999 is about 8024.9609967900. The cubic root of 64399999 is about 400.8316011507.

The spelling of 64399999 in words is "sixty-four million, three hundred ninety-nine thousand, nine hundred ninety-nine".