65899440 has 80 divisors (see below), whose sum is σ = 226994400. Its totient is φ = 17572608.

The previous prime is 65899417. The next prime is 65899451. The reversal of 65899440 is 4499856.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13095 + ... + 17414.

It is an arithmetic number, because the mean of its divisors is an integer number (2837430).

Almost surely, 2^65899440 is an apocalyptic number.

65899440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

65899440 is an abundant number, since it is smaller than the sum of its proper divisors (161094960).

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

65899440 is a wasteful number, since it uses less digits than its factorization.

65899440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30531 (or 30519 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The square root of 65899440 is about 8117.8470052102. The cubic root of 65899440 is about 403.9186517255.

The spelling of 65899440 in words is "sixty-five million, eight hundred ninety-nine thousand, four hundred forty".