684872891 has 2 divisors, whose sum is σ = 684872892. Its totient is φ = 684872890.

The previous prime is 684872869. The next prime is 684872899. The reversal of 684872891 is 198278486.

It is a happy number.

684872891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 684872891 - 2¹⁴ = 684856507 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (684872899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342436445 + 342436446.

It is an arithmetic number, because the mean of its divisors is an integer number (342436446).

Almost surely, 2^684872891 is an apocalyptic number.

684872891 is a deficient number, since it is larger than the sum of its proper divisors (1).

684872891 is an equidigital number, since it uses as much as digits as its factorization.

684872891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1548288, while the sum is 53.

The square root of 684872891 is about 26170.0762513219. The cubic root of 684872891 is about 881.4614537029.

The spelling of 684872891 in words is "six hundred eighty-four million, eight hundred seventy-two thousand, eight hundred ninety-one".