687563640 has 448 divisors, whose sum is σ = 2620576800. Its totient is φ = 161243136.

The previous prime is 687563627. The next prime is 687563651. The reversal of 687563640 is 46365786.

687563640 is a `hidden beast` number, since 6 + 8 + 7 + 5 + 636 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 9418644 + ... + 9418716.

Almost surely, 2^687563640 is an apocalyptic number.

687563640 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 687563640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1310288400).

687563640 is an abundant number, since it is smaller than the sum of its proper divisors (1933013160).

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

687563640 is a wasteful number, since it uses less digits than its factorization.

687563640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The square root of 687563640 is about 26221.4347433545. The cubic root of 687563640 is about 882.6143158844.

The spelling of 687563640 in words is "six hundred eighty-seven million, five hundred sixty-three thousand, six hundred forty".