686477721600 has 1890 divisors, whose sum is σ = 2953249734260. Its totient is φ = 157659955200.

The previous prime is 686477721577. The next prime is 686477721661. The reversal of 686477721600 is 6127774686.

686477721600 is a `hidden beast` number, since 6 + 8 + 6 + 4 + 7 + 7 + 7 + 21 + 600 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 125 ways as a sum of consecutive naturals, for example, 36130406391 + ... + 36130406409.

Almost surely, 2^686477721600 is an apocalyptic number.

686477721600 is a gapful number since it is divisible by the number (60) 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 686477721600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1476624867130).

686477721600 is an abundant number, since it is smaller than the sum of its proper divisors (2266772012660).

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

686477721600 is an equidigital number, since it uses as much as digits as its factorization.

686477721600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97 (or 40 counting only the distinct ones).

The product of its (nonzero) digits is 4741632, while the sum is 54.

The spelling of 686477721600 in words is "six hundred eighty-six billion, four hundred seventy-seven million, seven hundred twenty-one thousand, six hundred".