65999988 has 24 divisors (see below), whose sum is σ = 171111360. Its totient is φ = 21999960.

The previous prime is 65999951. The next prime is 65999993. The reversal of 65999988 is 88999956.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 305448 + ... + 305663.

It is an arithmetic number, because the mean of its divisors is an integer number (7129640).

Almost surely, 2^65999988 is an apocalyptic number.

It is an amenable number.

65999988 is an abundant number, since it is smaller than the sum of its proper divisors (105111372).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

65999988 is a wasteful number, since it uses less digits than its factorization.

65999988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611124 (or 611116 counting only the distinct ones).

The product of its digits is 12597120, while the sum is 63.

The square root of 65999988 is about 8124.0376660870. The cubic root of 65999988 is about 404.1239775699.

The spelling of 65999988 in words is "sixty-five million, nine hundred ninety-nine thousand, nine hundred eighty-eight".