65856811865856 has 72 divisors (see below), whose sum is σ = 191209266294144. Its totient is φ = 19956609653760.

The previous prime is 65856811865809. The next prime is 65856811865863.

65856811865856 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×65856811865856² (a number of 28 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 7 ways as a sum of consecutive naturals, for example, 3897766876 + ... + 3897783771.

Almost surely, 2^{65856811865856} is an apocalyptic number.

65856811865856 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

65856811865856 is an abundant number, since it is smaller than the sum of its proper divisors (125352454428288).

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

65856811865856 is a wasteful number, since it uses less digits than its factorization.

65856811865856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7795550677 (or 7795550663 counting only the distinct ones).

The product of its digits is 3317760000, while the sum is 78.

The spelling of 65856811865856 in words is "sixty-five trillion, eight hundred fifty-six billion, eight hundred eleven million, eight hundred sixty-five thousand, eight hundred fifty-six".