687139712 has 128 divisors (see below), whose sum is σ = 1663334400. Its totient is φ = 276203520.

The previous prime is 687139681. The next prime is 687139751. The reversal of 687139712 is 217931786.

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

Its product of digits (127008) is a multiple of the sum of its prime divisors (432).

It is a congruent number.

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, 3081233 + ... + 3081455.

It is an arithmetic number, because the mean of its divisors is an integer number (12994800).

Almost surely, 2^687139712 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 687139712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (831667200).

687139712 is an abundant number, since it is smaller than the sum of its proper divisors (976194688).

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

687139712 is a wasteful number, since it uses less digits than its factorization.

687139712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 444 (or 432 counting only the distinct ones).

The product of its digits is 127008, while the sum is 44.

The square root of 687139712 is about 26213.3498813105. The cubic root of 687139712 is about 882.4328820867.

The spelling of 687139712 in words is "six hundred eighty-seven million, one hundred thirty-nine thousand, seven hundred twelve".