681992064 has 288 divisors, whose sum is σ = 2213040960. Its totient is φ = 201277440.

The previous prime is 681992053. The next prime is 681992093. The reversal of 681992064 is 460299186.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×681992064² = 930226350717960192, which contains 22 as substring.

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 35 ways as a sum of consecutive naturals, for example, 6035272 + ... + 6035384.

It is an arithmetic number, because the mean of its divisors is an integer number (7684170).

Almost surely, 2^681992064 is an apocalyptic number.

681992064 is a gapful number since it is divisible by the number (64) 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 681992064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1106520480).

681992064 is an abundant number, since it is smaller than the sum of its proper divisors (1531048896).

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

681992064 is a wasteful number, since it uses less digits than its factorization.

681992064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190 (or 162 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The square root of 681992064 is about 26114.9777713863. The cubic root of 681992064 is about 880.2237998282.

The spelling of 681992064 in words is "six hundred eighty-one million, nine hundred ninety-two thousand, sixty-four".