65555999 has 2 divisors, whose sum is σ = 65556000. Its totient is φ = 65555998.

The previous prime is 65555993. The next prime is 65556013. The reversal of 65555999 is 99955556.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-65555999 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 65555999.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65555993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32777999 + 32778000.

It is an arithmetic number, because the mean of its divisors is an integer number (32778000).

Almost surely, 2^65555999 is an apocalyptic number.

65555999 is a deficient number, since it is larger than the sum of its proper divisors (1).

65555999 is an equidigital number, since it uses as much as digits as its factorization.

65555999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2733750, while the sum is 53.

The square root of 65555999 is about 8096.6659187594. The cubic root of 65555999 is about 403.2157427998.

The spelling of 65555999 in words is "sixty-five million, five hundred fifty-five thousand, nine hundred ninety-nine".