684273991 has 2 divisors, whose sum is σ = 684273992. Its totient is φ = 684273990.

The previous prime is 684273979. The next prime is 684274039. The reversal of 684273991 is 199372486.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 684273991 - 2¹⁵ = 684241223 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (684273691) 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 as a sum of consecutive naturals, namely, 342136995 + 342136996.

It is an arithmetic number, because the mean of its divisors is an integer number (342136996).

Almost surely, 2^684273991 is an apocalyptic number.

684273991 is a deficient number, since it is larger than the sum of its proper divisors (1).

684273991 is an equidigital number, since it uses as much as digits as its factorization.

684273991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 49.

The square root of 684273991 is about 26158.6312906467. The cubic root of 684273991 is about 881.2044419149.

The spelling of 684273991 in words is "six hundred eighty-four million, two hundred seventy-three thousand, nine hundred ninety-one".