681871536 has 120 divisors (see below), whose sum is σ = 1990317056. Its totient is φ = 217676160.

The previous prime is 681871523. The next prime is 681871571. The reversal of 681871536 is 635178186.

It is a junction number, because it is equal to n+sod(n) for n = 681871491 and 681871500.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 459051 + ... + 460533.

Almost surely, 2^681871536 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 681871536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (995158528).

681871536 is an abundant number, since it is smaller than the sum of its proper divisors (1308445520).

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

681871536 is a wasteful number, since it uses less digits than its factorization.

681871536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1631 (or 1622 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 681871536 is about 26112.6700281683. The cubic root of 681871536 is about 880.1719429859.

The spelling of 681871536 in words is "six hundred eighty-one million, eight hundred seventy-one thousand, five hundred thirty-six".