65613618640 has 40 divisors (see below), whose sum is σ = 153465177600. Its totient is φ = 26088283776.

The previous prime is 65613618619. The next prime is 65613618649. The reversal of 65613618640 is 4681631656.

65613618640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65613618649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2442240 + ... + 2468959.

It is an arithmetic number, because the mean of its divisors is an integer number (3836629440).

Almost surely, 2^65613618640 is an apocalyptic number.

It is an amenable number.

65613618640 is an abundant number, since it is smaller than the sum of its proper divisors (87851558960).

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

65613618640 is a wasteful number, since it uses less digits than its factorization.

65613618640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4911379 (or 4911373 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 46.

The spelling of 65613618640 in words is "sixty-five billion, six hundred thirteen million, six hundred eighteen thousand, six hundred forty".