65399840 has 48 divisors (see below), whose sum is σ = 168557760. Its totient is φ = 23781120.

The previous prime is 65399837. The next prime is 65399857. The reversal of 65399840 is 4899356.

65399840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a junction number, because it is equal to n+sod(n) for n = 65399791 and 65399800.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16820 + ... + 20339.

It is an arithmetic number, because the mean of its divisors is an integer number (3511620).

Almost surely, 2^65399840 is an apocalyptic number.

It is an amenable number.

65399840 is an abundant number, since it is smaller than the sum of its proper divisors (103157920).

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

65399840 is a wasteful number, since it uses less digits than its factorization.

65399840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37185 (or 37177 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 44.

The square root of 65399840 is about 8087.0167552689. The cubic root of 65399840 is about 402.8953254939.

The spelling of 65399840 in words is "sixty-five million, three hundred ninety-nine thousand, eight hundred forty".