686216756009664 has 504 divisors, whose sum is σ = 2240786176188560. Its totient is φ = 200468081848320.

The previous prime is 686216756009567. The next prime is 686216756009669. The reversal of 686216756009664 is 466900657612686.

686216756009664 is a `hidden beast` number, since 6 + 8 + 6 + 2 + 1 + 6 + 7 + 5 + 600 + 9 + 6 + 6 + 4 = 666.

It is a super-2 number, since 2×686216756009664² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 686216756009592 and 686216756009601.

It is not an unprimeable number, because it can be changed into a prime (686216756009669) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 279863307 + ... + 282304629.

Almost surely, 2^{686216756009664} is an apocalyptic number.

686216756009664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686216756009664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1120393088094280).

686216756009664 is an abundant number, since it is smaller than the sum of its proper divisors (1554569420178896).

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

686216756009664 is a wasteful number, since it uses less digits than its factorization.

686216756009664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2441509 (or 2441485 counting only the distinct ones).

The product of its (nonzero) digits is 940584960, while the sum is 72.

The spelling of 686216756009664 in words is "six hundred eighty-six trillion, two hundred sixteen billion, seven hundred fifty-six million, nine thousand, six hundred sixty-four".