681993312 has 384 divisors, whose sum is σ = 2471067648. Its totient is φ = 158976000.

The previous prime is 681993259. The next prime is 681993313. The reversal of 681993312 is 213399186.

It is a super-2 number, since 2×681993312² = 930229755225458688, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681993313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4516437 + ... + 4516587.

It is an arithmetic number, because the mean of its divisors is an integer number (6435072).

Almost surely, 2^681993312 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 681993312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1235533824).

681993312 is an abundant number, since it is smaller than the sum of its proper divisors (1789074336).

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

681993312 is a wasteful number, since it uses less digits than its factorization.

681993312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242 (or 234 counting only the distinct ones).

The product of its digits is 69984, while the sum is 42.

The square root of 681993312 is about 26115.0016657093. The cubic root of 681993312 is about 880.2243367448.

The spelling of 681993312 in words is "six hundred eighty-one million, nine hundred ninety-three thousand, three hundred twelve".