681560249 has 4 divisors (see below), whose sum is σ = 682547280. Its totient is φ = 680573220.

The previous prime is 681560197. The next prime is 681560263. The reversal of 681560249 is 942065186.

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 681560249 - 2¹² = 681556153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681560279) 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, 492479 + ... + 493860.

It is an arithmetic number, because the mean of its divisors is an integer number (170636820).

Almost surely, 2^681560249 is an apocalyptic number.

It is an amenable number.

681560249 is a deficient number, since it is larger than the sum of its proper divisors (987031).

681560249 is an equidigital number, since it uses as much as digits as its factorization.

681560249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 987030.

The product of its (nonzero) digits is 103680, while the sum is 41.

The square root of 681560249 is about 26106.7088887129. The cubic root of 681560249 is about 880.0379843281.

The spelling of 681560249 in words is "six hundred eighty-one million, five hundred sixty thousand, two hundred forty-nine".