687698509212 has 180 divisors, whose sum is σ = 2123683581096. Its totient is φ = 192363050880.

The previous prime is 687698509159. The next prime is 687698509219. The reversal of 687698509212 is 212905896786.

687698509212 is a `hidden beast` number, since 68 + 7 + 69 + 8 + 509 + 2 + 1 + 2 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 687698509212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687698509219) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 31438 + ... + 1173194.

Almost surely, 2^687698509212 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 687698509212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1061841790548).

687698509212 is an abundant number, since it is smaller than the sum of its proper divisors (1435985071884).

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

687698509212 is a wasteful number, since it uses less digits than its factorization.

687698509212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1141810 (or 1141786 counting only the distinct ones).

The product of its (nonzero) digits is 26127360, while the sum is 63.

The spelling of 687698509212 in words is "six hundred eighty-seven billion, six hundred ninety-eight million, five hundred nine thousand, two hundred twelve".