681021072 has 60 divisors (see below), whose sum is σ = 1912536444. Its totient is φ = 226218240.

The previous prime is 681021067. The next prime is 681021091. The reversal of 681021072 is 270120186.

It can be written as a sum of positive squares in 2 ways, for example, as 491242896 + 189778176 = 22164^2 + 13776^2 .

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 11 ways as a sum of consecutive naturals, for example, 34122 + ... + 50262.

Almost surely, 2^681021072 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 681021072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (956268222).

681021072 is an abundant number, since it is smaller than the sum of its proper divisors (1231515372).

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

681021072 is a wasteful number, since it uses less digits than its factorization.

681021072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16448 (or 16439 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 681021072 is about 26096.3804386739. The cubic root of 681021072 is about 879.8058593768.

The spelling of 681021072 in words is "six hundred eighty-one million, twenty-one thousand, seventy-two".