681919992 has 128 divisors (see below), whose sum is σ = 2083737600. Its totient is φ = 205317504.

The previous prime is 681919981. The next prime is 681920017. The reversal of 681919992 is 299919186.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 129393 + ... + 134559.

It is an arithmetic number, because the mean of its divisors is an integer number (16279200).

Almost surely, 2^681919992 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 681919992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1041868800).

681919992 is an abundant number, since it is smaller than the sum of its proper divisors (1401817608).

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

681919992 is a wasteful number, since it uses less digits than its factorization.

681919992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5242 (or 5232 counting only the distinct ones).

The product of its digits is 629856, while the sum is 54.

The square root of 681919992 is about 26113.5978371422. The cubic root of 681919992 is about 880.1927917818.

The spelling of 681919992 in words is "six hundred eighty-one million, nine hundred nineteen thousand, nine hundred ninety-two".