687851136 has 128 divisors (see below), whose sum is σ = 2320214400. Its totient is φ = 196521984.

The previous prime is 687851117. The next prime is 687851141. The reversal of 687851136 is 631158786.

687851136 is a `hidden beast` number, since 68 + 78 + 511 + 3 + 6 = 666.

687851136 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 (128).

It is a junction number, because it is equal to n+sod(n) for n = 687851091 and 687851100.

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, 9976 + ... + 38408.

It is an arithmetic number, because the mean of its divisors is an integer number (18126675).

Almost surely, 2^687851136 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 687851136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1160107200).

687851136 is an abundant number, since it is smaller than the sum of its proper divisors (1632363264).

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

687851136 is a wasteful number, since it uses less digits than its factorization.

687851136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28463 (or 28445 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 687851136 is about 26226.9162502952. The cubic root of 687851136 is about 882.7373167295.

It can be divided in two parts, 68 and 7851136, that added together give a square (7851204 = 2802²).

The spelling of 687851136 in words is "six hundred eighty-seven million, eight hundred fifty-one thousand, one hundred thirty-six".