687735296640 has 768 divisors, whose sum is σ = 2899802880000. Its totient is φ = 146689449984.

The previous prime is 687735296629. The next prime is 687735296693. The reversal of 687735296640 is 46692537786.

687735296640 is a `hidden beast` number, since 6 + 8 + 7 + 7 + 3 + 529 + 66 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 51320661 + ... + 51334059.

It is an arithmetic number, because the mean of its divisors is an integer number (3775785000).

Almost surely, 2^687735296640 is an apocalyptic number.

687735296640 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 687735296640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1449901440000).

687735296640 is an abundant number, since it is smaller than the sum of its proper divisors (2212067583360).

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

687735296640 is a wasteful number, since it uses less digits than its factorization.

687735296640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13517 (or 13502 counting only the distinct ones).

The product of its (nonzero) digits is 91445760, while the sum is 63.

The spelling of 687735296640 in words is "six hundred eighty-seven billion, seven hundred thirty-five million, two hundred ninety-six thousand, six hundred forty".