687955840 has 128 divisors (see below), whose sum is σ = 1932426720. Its totient is φ = 230891520.

The previous prime is 687955823. The next prime is 687955861. The reversal of 687955840 is 48559786.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (52).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 87762 + ... + 95278.

Almost surely, 2^687955840 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 687955840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (966213360).

687955840 is an abundant number, since it is smaller than the sum of its proper divisors (1244470880).

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

687955840 is a wasteful number, since it uses less digits than its factorization.

687955840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7560 (or 7548 counting only the distinct ones).

The product of its (nonzero) digits is 2419200, while the sum is 52.

The square root of 687955840 is about 26228.9122915915. The cubic root of 687955840 is about 882.7821042491.

The spelling of 687955840 in words is "six hundred eighty-seven million, nine hundred fifty-five thousand, eight hundred forty".