65978685655 has 16 divisors (see below), whose sum is σ = 79466960160. Its totient is φ = 52588268928.

The previous prime is 65978685649. The next prime is 65978685691. The reversal of 65978685655 is 55658687956.

It is a cyclic number.

It is not a de Polignac number, because 65978685655 - 2¹⁹ = 65978161367 is a prime.

It is a super-2 number, since 2×65978685655² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

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, 1549429 + ... + 1591441.

It is an arithmetic number, because the mean of its divisors is an integer number (4966685010).

Almost surely, 2^65978685655 is an apocalyptic number.

65978685655 is a deficient number, since it is larger than the sum of its proper divisors (13488274505).

65978685655 is a wasteful number, since it uses less digits than its factorization.

65978685655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43170.

The product of its digits is 544320000, while the sum is 70.

The spelling of 65978685655 in words is "sixty-five billion, nine hundred seventy-eight million, six hundred eighty-five thousand, six hundred fifty-five".