687649655 has 48 divisors (see below), whose sum is σ = 1041741120. Its totient is φ = 426539520.

The previous prime is 687649639. The next prime is 687649667. The reversal of 687649655 is 556946786.

It is a happy number.

It is not a de Polignac number, because 687649655 - 2⁴ = 687649639 is a prime.

Its product of digits (10886400) is a multiple of the sum of its prime factors (840).

It is a self number, because there is not a number n which added to its sum of digits gives 687649655.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1681091 + ... + 1681499.

It is an arithmetic number, because the mean of its divisors is an integer number (21702940).

Almost surely, 2^687649655 is an apocalyptic number.

687649655 is a deficient number, since it is larger than the sum of its proper divisors (354091465).

687649655 is a wasteful number, since it uses less digits than its factorization.

687649655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 840 (or 829 counting only the distinct ones).

The product of its digits is 10886400, while the sum is 56.

The square root of 687649655 is about 26223.0748578423. The cubic root of 687649655 is about 882.6511197041.

The spelling of 687649655 in words is "six hundred eighty-seven million, six hundred forty-nine thousand, six hundred fifty-five".