681110640 has 320 divisors, whose sum is σ = 2712683520. Its totient is φ = 153861120.

The previous prime is 681110629. The next prime is 681110657. The reversal of 681110640 is 46011186.

681110640 is a `hidden beast` number, since 6 + 8 + 1 + 1 + 10 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1617630 + ... + 1618050.

It is an arithmetic number, because the mean of its divisors is an integer number (8477136).

Almost surely, 2^681110640 is an apocalyptic number.

681110640 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 681110640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1356341760).

681110640 is an abundant number, since it is smaller than the sum of its proper divisors (2031572880).

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

681110640 is a wasteful number, since it uses less digits than its factorization.

681110640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 557 (or 545 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 681110640 is about 26098.0964823107. The cubic root of 681110640 is about 879.8444284216.

The spelling of 681110640 in words is "six hundred eighty-one million, one hundred ten thousand, six hundred forty".