687815940 has 144 divisors (see below), whose sum is σ = 2301227712. Its totient is φ = 152941824.

The previous prime is 687815929. The next prime is 687815951. The reversal of 687815940 is 49518786.

It is an interprime number because it is at equal distance from previous prime (687815929) and next prime (687815951).

It is a self number, because there is not a number n which added to its sum of digits gives 687815940.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 105619 + ... + 111941.

It is an arithmetic number, because the mean of its divisors is an integer number (15980748).

Almost surely, 2^687815940 is an apocalyptic number.

687815940 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 687815940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1150613856).

687815940 is an abundant number, since it is smaller than the sum of its proper divisors (1613411772).

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

687815940 is a wasteful number, since it uses less digits than its factorization.

687815940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6386 (or 6377 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 48.

The square root of 687815940 is about 26226.2452516558. The cubic root of 687815940 is about 882.7222604909.

The spelling of 687815940 in words is "six hundred eighty-seven million, eight hundred fifteen thousand, nine hundred forty".