65078646640 has 80 divisors (see below), whose sum is σ = 175006798848. Its totient is φ = 22043835648.

The previous prime is 65078646433. The next prime is 65078646641. The reversal of 65078646640 is 4664687056.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65078646641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 653592 + ... + 746551.

Almost surely, 2^65078646640 is an apocalyptic number.

It is an amenable number.

65078646640 is an abundant number, since it is smaller than the sum of its proper divisors (109928152208).

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

65078646640 is a wasteful number, since it uses less digits than its factorization.

65078646640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1400246 (or 1400240 counting only the distinct ones).

The product of its (nonzero) digits is 5806080, while the sum is 52.

The spelling of 65078646640 in words is "sixty-five billion, seventy-eight million, six hundred forty-six thousand, six hundred forty".