681907849 has 4 divisors (see below), whose sum is σ = 779323264. Its totient is φ = 584492436.

The previous prime is 681907847. The next prime is 681907861. The reversal of 681907849 is 948709186.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 681907849 - 2¹ = 681907847 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 681907796 and 681907805.

It is not an unprimeable number, because it can be changed into a prime (681907847) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48707697 + ... + 48707710.

It is an arithmetic number, because the mean of its divisors is an integer number (194830816).

Almost surely, 2^681907849 is an apocalyptic number.

It is an amenable number.

681907849 is a deficient number, since it is larger than the sum of its proper divisors (97415415).

681907849 is an equidigital number, since it uses as much as digits as its factorization.

681907849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97415414.

The product of its (nonzero) digits is 870912, while the sum is 52.

The square root of 681907849 is about 26113.3653327180. The cubic root of 681907849 is about 880.1875671980.

The spelling of 681907849 in words is "six hundred eighty-one million, nine hundred seven thousand, eight hundred forty-nine".