681879187 has 4 divisors (see below), whose sum is σ = 743868216. Its totient is φ = 619890160.

The previous prime is 681879151. The next prime is 681879217. The reversal of 681879187 is 781978186.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 681879187 - 2¹⁹ = 681354899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681879127) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 30994498 + ... + 30994519.

It is an arithmetic number, because the mean of its divisors is an integer number (185967054).

Almost surely, 2^681879187 is an apocalyptic number.

681879187 is a deficient number, since it is larger than the sum of its proper divisors (61989029).

681879187 is a wasteful number, since it uses less digits than its factorization.

681879187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61989028.

The product of its digits is 1354752, while the sum is 55.

The square root of 681879187 is about 26112.8165275215. The cubic root of 681879187 is about 880.1752349894.

The spelling of 681879187 in words is "six hundred eighty-one million, eight hundred seventy-nine thousand, one hundred eighty-seven".