684391671 has 6 divisors (see below), whose sum is σ = 988565760. Its totient is φ = 456261108.

The previous prime is 684391651. The next prime is 684391679. The reversal of 684391671 is 176193486.

It is a happy number.

It is not a de Polignac number, because 684391671 - 2¹⁹ = 683867383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684391679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 38021751 + ... + 38021768.

It is an arithmetic number, because the mean of its divisors is an integer number (164760960).

Almost surely, 2^684391671 is an apocalyptic number.

684391671 is a deficient number, since it is larger than the sum of its proper divisors (304174089).

684391671 is a wasteful number, since it uses less digits than its factorization.

684391671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76043525 (or 76043522 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 684391671 is about 26160.8805471070. The cubic root of 684391671 is about 881.2549549140.

The spelling of 684391671 in words is "six hundred eighty-four million, three hundred ninety-one thousand, six hundred seventy-one".