684545731 has 2 divisors, whose sum is σ = 684545732. Its totient is φ = 684545730.

The previous prime is 684545713. The next prime is 684545753. The reversal of 684545731 is 137545486.

684545731 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

Together with previous prime (684545713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 684545731 - 2¹¹ = 684543683 is a prime.

It is a super-2 number, since 2×684545731² = 937205715660648722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (684545761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342272865 + 342272866.

It is an arithmetic number, because the mean of its divisors is an integer number (342272866).

Almost surely, 2^684545731 is an apocalyptic number.

684545731 is a deficient number, since it is larger than the sum of its proper divisors (1).

684545731 is an equidigital number, since it uses as much as digits as its factorization.

684545731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 403200, while the sum is 43.

The square root of 684545731 is about 26163.8248541760. The cubic root of 684545731 is about 881.3210749241.

The spelling of 684545731 in words is "six hundred eighty-four million, five hundred forty-five thousand, seven hundred thirty-one".