681787049 has 8 divisors (see below), whose sum is σ = 701941320. Its totient is φ = 661723776.

The previous prime is 681787039. The next prime is 681787063. The reversal of 681787049 is 940787186.

681787049 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 457746025 + 224041024 = 21395^2 + 14968^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-681787049 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 681786988 and 681787006.

It is not an unprimeable number, because it can be changed into a prime (681787039) 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, 7394 + ... + 37659.

It is an arithmetic number, because the mean of its divisors is an integer number (87742665).

Almost surely, 2^681787049 is an apocalyptic number.

It is an amenable number.

681787049 is a deficient number, since it is larger than the sum of its proper divisors (20154271).

681787049 is a wasteful number, since it uses less digits than its factorization.

681787049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45499.

The product of its (nonzero) digits is 677376, while the sum is 50.

The square root of 681787049 is about 26111.0522384679. The cubic root of 681787049 is about 880.1355890421.

The spelling of 681787049 in words is "six hundred eighty-one million, seven hundred eighty-seven thousand, forty-nine".