681151985 has 8 divisors (see below), whose sum is σ = 818245800. Its totient is φ = 544345984.

The previous prime is 681151973. The next prime is 681151987. The reversal of 681151985 is 589151186.

681151985 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 53699584 + 627452401 = 7328^2 + 25049^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 681151985 - 2⁶ = 681151921 is a prime.

It is not an unprimeable number, because it can be changed into a prime (681151987) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66710 + ... + 76239.

It is an arithmetic number, because the mean of its divisors is an integer number (102280725).

Almost surely, 2^681151985 is an apocalyptic number.

It is an amenable number.

681151985 is a deficient number, since it is larger than the sum of its proper divisors (137093815).

681151985 is a wasteful number, since it uses less digits than its factorization.

681151985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143907.

The product of its digits is 86400, while the sum is 44.

The square root of 681151985 is about 26098.8885778686. Note that the first 3 decimals coincide. The cubic root of 681151985 is about 879.8622309291.

The spelling of 681151985 in words is "six hundred eighty-one million, one hundred fifty-one thousand, nine hundred eighty-five".