684450671491 has 2 divisors, whose sum is σ = 684450671492. Its totient is φ = 684450671490.

The previous prime is 684450671477. The next prime is 684450671521. The reversal of 684450671491 is 194176054486.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 684450671491 - 2¹⁹ = 684450147203 is a prime.

It is not a weakly prime, because it can be changed into another prime (684450671461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342225335745 + 342225335746.

It is an arithmetic number, because the mean of its divisors is an integer number (342225335746).

Almost surely, 2^684450671491 is an apocalyptic number.

684450671491 is a deficient number, since it is larger than the sum of its proper divisors (1).

684450671491 is an equidigital number, since it uses as much as digits as its factorization.

684450671491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5806080, while the sum is 55.

The spelling of 684450671491 in words is "six hundred eighty-four billion, four hundred fifty million, six hundred seventy-one thousand, four hundred ninety-one".